This year I took all of the fouls listed on page 77 and put them into a spread sheet, then sorted them by alphabet, so they would be scrambled (not all 5's together, etc) Then I printed it out. At least several times a week early in the season, I went through the list, asking myself, what is the penalty and what is the signal? There are something like 50 fouls listed. After about a week of doing it daily, I had it memorized very well. Practice Practice Practice!
After having it down, I went out on the field this year a lot more confident. My first white-hat game this year, my backjudge, who is a long-time friend and used to be a white-hat, called an invalid fair catch signal. I immediately gave the correct signal. Incidentally, it was the first and only PSK enforcement of the year. At half-time I challenged him to look it up and see if I was correct. He was pleasantly surprised.
It helped my credibility. When the white-hat knows what he is doing, the whole crew is more confident.
Practice Practice Practice - no gimmicks