I’m in my second week of flower, knowing that the plant will extend its growth in this period I removed all smaller leaves that were grown first, most fan leaves that block the light to the canopy, I am LST’ing a plant so my canopy is even so as far as small side stems I have few to trim - however you can see the difference between stems with tight nodes and a strong stem system when flowering, compared to those with only a flower filling on top. If I see a tiny popcorn flower sticking out by itself I’d clip it before it adds any new growth. Also all of the lower stem leaves I remove to promote new growth for the upper canopy but I am very reluctant to remove too many, I try not to disrupt any stems with good growth.
Once the plant really begins to produce flowers you don’t want to do much trimming if at all.