The Laws of the Game provides standard and approved signals for both the referee and assistant referees. Not using these signals can be confusing to players, spectators, and even members of the referee team.
For example, what is the approved signal for offside for the referee? On TV, you may see a top-level referee drawing an imaginary line with the finger as if to trace the offside line. But it is not the approved signal. The referee should instead blow their whistle and raise their hand to indicate that the restart is an indirect free kick.
Watch the video below. Ask yourself. Do you use these non-standard signals? Do you have these bad habits?