Be aware that I am not going to tell you how to write each section, but how to arrange your sections. I will also use some images for demonstration which are huge, but I need them big so don't freak out. They'll be in spoilers so the page size doesn't freak out. My terminology may not be standard, so don't freak out about that either.
Terminology
-Intro
This means the drum part of the song at the beginning that only exists to help the DJ mix.
-Outro
This means the cooldown/rythmic part at the end of the song, similar to the intro, to help out the DJ mix.
-Exposition
The exposition is basically just you fleshing out your melody so your audience will be familiar with it before the song really gets crazy. Generally you won't really have your drums going at this point, kind of a calm before the storm. This is how you start your track if you don't have an Intro.
-Buildup
A buildup happens when things start getting more intense. It could be a more energized drum pattern, addition of instruments that make you feel like something is brewing/coming up soon, or whatever. Realise the difference between what I call a "buildup" and a "riser".
-Riser
This is the part where you hear the drums getting more rapid, short repeated notes/samples, a rise in pitch in a synth, or whatever. Whatever it is, it quickly builds up a huge amount of tension right before the drop.
-Drop
Should be obvious. It's the big main focus of the track. The pinnacle, the most exciting, the largest part.
-Breakdown
This is the calm part in the middle of the track. Generally it doesn't have any drums. It's pretty chill and lasts as long as it possibly can before things start getting crazier.
-Rehash
What I mean by "rehash" is basically variation. Could be that the drum pattern is switched up, a new synth is added, or a new melody is introduced. Whatever it is, it's a variation on whatever type of section that it lies in, whether it's the intro, outro, exposition, buildup, riser, or drop. Between rehashes (and also arrangement sections) are great places to put your FX to help the transition, even if it's just a cymbal crash. (Also note that between sections are great places to put drum rolls.)
Arrangement
All EDM has basically the same structure. If you don't like it, get over it and conform.
- You start out with your intro. You may forgo this and start with your exposition. Intros generally last between 4 to 16 measures.
- Exposition. Flesh out the melody nicely for your audience before you go all crazy on them. Usually lasts about 4 to 8 measures.
- You then go to a buildup. Start making it sound like the song is going somewhere. Usually these last about 2 to 4 measures.
- Do a riser. This can be 1, 2, but generally not over 4 measures.
- Drop it hard. Drops are generally between 6 and 12 measures long. Every 2 to 4 measures, "rehash" or variate it.
- Move into your breakdown. Basically, you want it to last as long as you possibly can, but use common sense.
- Make a buildup happen. You don't want to sit in your breakdown forever, because that's boring.
- Riser again.
- Drop it again! This can often be shorter than your first drop, and might last only 8-10 measures, but whatever you feel like.
- Outro.
That's all there is to it!
There is certain amount of variation you can apply to this model, but it's effectively the same in any EDM song ever made. You can do multiple buildups/risers that build into more buildups/risers. You can even add buildups/risers into your intro. Sections can overlap and last as long as you please. Common sense is the key here as well.
Examples
Examples can be very enlightening. You can use someone else's arrangement if you please; there's no shame in that. "Lesser artists borrow, great artists steal" - Stravinsky.
I'll show you a couple of songs' arrangements. I know my labeling is not perfect, so don't freak out about it.
Spoiler images:
Conclusion
You may need to practice on how to make each section pleasing to listen to, but you should have good arrangement now if you follow this guide.