I usually focus on 8 patterns in a bank (top row) Section A will usually occupy patterns 1-4 , in which the pattern gets progressively more complex / busy starting from pattern 1 up through 4. Section B will be patterns 5-6 and will be more of a bridge of sorts, which will have different notation but most of the same sounds and in the same scale, and build complexity over patterns 5-6. After the bridge, I move on to patterns 7-8 which is traditionally section A again, just the finale, in which the patterns are most intense at this point. That’s it!
Most of the patterns I do will have trig conditions added and use track scaling to make them much more long and varied. I also multitrack live takes and pick the best one. Afterwards if something is off, I can typically rearrange, cut, or add some things in Cubase, since all the stems are there.
None of these rules are set in stone. Sometimes I’ve just rode out the B section and never went back to A. I’ve done full songs that only utilize 2 patterns but did live track mute / un-mute. I’ve switched patterns prematurely or too late unintentional, but decided to keep it because it sounded good. Just remember to have fun!