I'm still not sure exactly what it is you actually wish to achieve. What do you want your end result to be?
A composition, or a composition in sheet music form, or both?
I get the impression that you are not a stranger to composition. Have you composed other types of music i.e. orchestral?
As before, I don't think that you will necessarily find a 'blueprint' for specific genres of music.
Try listening to several pieces of music which fall under the category of 'trance' for example (if that's what you wish to produce) with a pen and some paper and break the songs down into:
A) Tracks / instruments (i.e. Bass/kick drum/hi hats/snares/
synth1/synth2 etc)
B) How is the song structured (you could either split the song into sections line Intro/breakdown/Euphoric section etc etc or alternatively, just make a note of when each new instrument comes into the song.
C) Try to get a feel for the mood of the song. I know that trance music is supposed to invoke feelings of euphoria whilst at the same time making you want to dance your *** off but try to pick apart why a certain song sounds euphoric, is it the chord progression of the synth string or pad, is the lead melody or some other factor? What is it about the song that makes you tap your feet? It could be something as simple as the kick drum sample used or alternatively the pumping bassline etc…
Be mindful of the fact that you don't necessarily have to then make a carbon copy of the format of a particular song but it may help to simply copy the format of a particular song you like to being with. With most trance songs you will notice similarities in the way such songs are structured and will hopefully then be able to have a go yourself.
I used to play keyboards in a guitar based indie style band but have always been into house music of any style and often thought that trance sounded really easy to produce.
How wrong was I?
For me, coming up with synth melodies has never been a major problem. However, constructing an entire song around a single synth riff and then making it sound good was something I found to be surprisingly difficult!
If this is something you are seriously interested in doing, persevere.
There will be times when you really don't want to go and sit staring at your computer making music and I think we all get that sometimes. If you feel like this, have a few days/weeks break from it and go back.
Even professional musicians will no doubt experience the feeling of monotony as will the guys on this forum!