In low energy tanks, I just trim them and plant them. HIgher energy, I group a few stems together with a cable tie or similar, being careful not to crush the stems, and then place a stone in the "cup".
One of the problems is people nip of cuttigs with their fingers, crush a few stems together and shove it in the gravel. The damaged material then, quite naturally rots away, freeing the top part of the cutting to float away.
Sharp tools, clean cuts, minimal damage and a little care.