OK, so there's a few different things going on here to your question.
You're asking about how to do this for a specific style, not just in general, so there's a bit of a difference in the answer in detail, but...
Let's start at the basics and come back to Shpongle-ish style after and apply the basics in that form.
The basic concept of a transition is to prime the ear for what comes next. It's akin to foreshadowing mixed with a clock's chime. It let's you know that it's time for a change, and what the nature of that change is going to be.
What jars is when you set up a transition that offers one kind of perception, but the part that follows goes an entirely different route all-together (sometimes this is a useful tool to use on purpose, but for the moment, we'll dash it out as "wrong").
But let's back up a few bars. Before there's a transition, there's markers already to inform you of cycles in the tone.
The most basic of these is an open high hat.
So let's say you have four on the floor, a snare every other, a closed high-hat every 8th.
After two bars (two cycles of four kicks), in traditional music forms, you would end the second bar after the snare with an open high hat just before you start the third bar.
This is not a transition. However, it already informs us that this is our cycle.
Traditionally, we would run this cycle either once again, or three times more. We'll keep it simple and just do it once more.
Alright, let's set up a basic set, keeping in mind we only have drums in this example.
A first bar (S.A.1) of our example is comprised of:
KD = Kick Drum, SD = Snare Drum, HC = High Hat Closed, HO = High Hat Open
(We're in 8th note presentation here)
Our second bar (S.A.2) of our example is comprised of:
Together, we have:
This is equal to S.A.1 | S.A.2
Now let's set up the bare minimum of our arrangement like a drum machine.
S.A.1 | S.A.2 | S.A.1 | S.A.2
Let's organize this a bit further by adding a label for the second half of our arrangement.
S.A.1 | S.A.2 | S.B.1 | S.B.2
There we go, now we can discuss the second half separate from the first.
Alright, that gets us our very basic set up, but we need to prime for our change that's going to happen after section B.
Now instead of just an open high hat, we're going to add a bit more so that we not only know that we're at the end of the cycle, which we already expect thanks to S.A.2's information of the Open High Hat at the end, but that we're also going to change everything up.
In this example, we'll assume that we're going to "pick up" the energy after section B (traditional approach).
So we would typically pick harder hitting components to inform that we're going to pick up the energy, as opposed to the softer open high hat which we softly used to inform the end of a cycle previously.
Traditionally, this was done with a Snare and a juxtaposition of the Snare and Kick in a stumble, or "Break Beat" (yep; that's where that comes from).
To show a break beat right, I'll need to convert to 16th's instead of just 8ths:
So it might look something like:
We've sandwiched in an extra snare right after the third kick drum (a 16th note after, in fact) and this lands the snare in between the closed high hat and kick, all by itself, and out of step with everything else. Ergo the term "break beat" because it literally breaks from the beat's normal pattern in the rest of the bars.
So this break beat will be S.B.2
So if we break everything out to 16ths, then we have
This is the same as the summary form of: S.A.1 | S.A.2 | S.B.1 | S.B.2|
That now allows us to break out into an C Section (aaand I hear the puns coming!)
Now, to top this off, we have to hit the start of C with something that is different than what we have had so far in sound that clearly notes that we're in a bigger and more vibrant part; a CLEAR marker that stands out from the rest.
Traditionally, this was accomplished with a Cymbal because, like a Moog, it absolutely cuts through all sounds going on and you could easily hear that "HEY! WE'RE IN A NEW PART OF THE SONG NOW!" even if you missed the break beat because it was drowned out by how crappy drums used to be acoustically in "ye ol days" (thank you Tom Petty for pushing the Kick Drum in popular rock music).
So Section C would start on the Kick with a Cymbal hit to finish off the transition.
THE MEANING OF ALL OF THAT?
The take away is that a transition isn't a thing you can put your finger on like a verse, chorus, or bridge.
Instead, it's a style of playing a verse or chorus near the edges of the cycle on both ends that influences the ear to understanding a change up is going to happen.
Traditionally, there is no such thing as a transition that IS HAPPENING.
There is a transition that IS COMING (S.B.2 tells us that a transition is coming) and a transition THAT HAPPENED (S.C.1's cymbal told us that a transition just happened).
Think of transitions like this:
You don't have a transition to an Off Ramp on a highway.
You have a sign that tells you that you have an Off Ramp coming, and then you're on the Off Ramp with a sign saying that you're on that Off Ramp.
(it's not a perfect analogy, but it'll do).
So that wraps up the traditional basics of the mythical transitions.
They get more complicated the more you have going on, and vary depending on what instruments you have going on.
BUT - the basics of a transition will typically be the same even with instruments instead of drums.
Take for instance a build, and we'll imagine you do this without drums and only rises.
That has been primed by how long your phrases are (in cookie-cutter EDM, typically 8 bar loops in pairs, so it'll probably be around 8 bars for the build).
And the intensity is accomplished (most often) in volume increase and sequence holding getting shorter and shorter until it reaches a climactic final bar.
Then we can look at the chordal variation. The chords of the harmonies would pull and pull on a tension to build the same kind of rise without the volume and sequence holding techniques (though they may indeed increase in volume sometimes); notes may stretch out and become longer a bit for some of the instruments so that dissonance is created by other notes play over it that previously did not, and other instruments may increase their rate of notes.
In both cases, the build up will release to an abrupt explosion of some kind just like the cymbal was doing for the drums; either by a key change, or sudden hard hit of snyths, or stab, etc...
These are variously accomplishing the same thing, however, as the very basic outline of the drums in the first example.
NOW...SHPONGLE, or HOW TO TRANSITION IN TRANSIENT MUSIC
Shpongle is a variation of transient music; that is, music which is never really solidly in one place or another in its form, but instead always in route to moving to another part of itself - like rolling waves on the ocean.
You can clearly point to one wave or another, but the more that you attempt to describe where one wave began or ended, the harder it becomes the closer that you look.
This is accomplished the EXACT SAME WAY as the drum example, BUT, it's doing so over a LONGER span, AND, it's doing so MOSTLY without employing drums AS the informer of the changes.
Further, the changes are more whispered into your ear ahead of time rather than "told" to you overtly like the drum example, or any of the previous examples.
In this mode, you instead rely on your FADERS more than anything else to smoothly migrate from one part to the other and build your transitions.
The "whisper" occurs because you take a component of the part coming up and softly introduce just that component in the part already playing and slowly rise the volume of it.
After you do this for a while, you introduce another component of the section coming up, and another, etc... as fitting.
While rising those, you start looking for what to drop a bit on the fader from the part you are leaving.
Once you have migrated to the new part, you KEEP (important part here) a tiny scratch of what you left behind running for a bit before you drop it out (if you are going to drop it at all).
It's also important to create the allusion of morphing.
So you have a vocal throat singing going on, and that throat singing may have an oscillation to it that is around the 8th note timing. You tuck that in your hat and later when you're doing the transitions and know that you want to pull drums in, you softly introduce a shaker at 8th beat intervals.
You also know that you want a snare eventually, and you want some chanting.
So you take that shaker and make every 3rd 8th note slightly more vibrant/louder than the others (this is priming for a snare's typical timing).
You've now primed for 4 on the floor with a shaker and done it very softly and subtly.
Then you bring in the chanting which happens, say, every 3rd 8th (or, you should line it up that way) and you let that run on reverb in the background.
Now that you've taken the time to layer all that in softly over time, you begin to bring in a Kick, but the kick that you bring is soft - the top frequency of your kick and not the bottom, and you slowly migrate that kick to include the bottom frequency of itself as well.
Once that happens, you start dropping the throat singing and leaning more on those chants and increase your pads because HEY, WE'RE GOING TO CHANGE HERE!
And then you fade, a bit more quickly than before, your new sections pads in and add a one-off slow cymbal or pad that's left reverbing or echoing off until it's just drowned out naturally, and you defuse the chanting and either bring in the snare, or increase it.
Now you have transitioned into a 4 on the floor backing for your transient/ambient song and left your beatless intro.
After a while of sitting on the four on the floor, around those marking points we talked about before (but instead of 2 bars, more like 4 or 6 bar cycles because it's ambient music) you start introducing one-off displacements of the Kick drum and/or Snare, and start making your way to changing the drums entirely from something like four on the floor to a longer format of only one kick and snare per bar (sort of like R&B, or casual rock - or Cusco, to stick with ambient music) and etc...
Hope that helps some.
That's my 2 nuyen.