my considerations (one way i try, have not yet reached) …
with the basic idea of an motif you can begin to create from that point … first write the max highlight of the motiv down in renoise (use at this point a simple synth sound/piano to get an insight into how it can listen to later), then you have it, programm the synth to fit the motiv best AND stay awy from changing the motiv to fit a preset!
After having the main, you can create all the other elements around this part and in link to it.
It is good to programm/search the sounds little by little to take place in the spectrum without beating each other. So you must not heavy eq if you take advantage how you set from the first element in the whole spectrum.
Ask youself: What is the direkt way from your basic idea to the result? Fit it with more and more tracks … or can you reach it with less but, catchy living parts?
Decrease complexity to the needed minimum