The only condition to grow the moss is low temperature. But not as long as 0-20C. Too cold will stunt the grow. 22-26C is the best temperature to grow them. Max 6 hours of photoperiod. Liquid fertilizer is a must. You can make it as daily or weekly. Iron/fe is important for the mosses.
I had tried all kind of liquid fertilizer. The best still the ADA Brighty K + Step 2 or Brighty Shade.
Trimming part just like you trimming other aquatic plants. But for the mosses, you can trim it as whatever shape you like to have.