About 5 years ago I got very tired of watching everyone else hit Royals because I had NEVER hit one! I decided to get serious. I asked a very knowledgable player who I had seen hit lots of Royals how he did it. He told me to go to BobDancer.com and get all of his materials and to study it carefully. There are a lot of different games too and they all have differing strategy on how to hold cards. I studied for about 4 weeks and on my next trip to Vegas I hit 9 royals in 4 days, including 4 in one night on different machines. I would highly recommend getting the strategy cards and using them until you have the hand rankings down pat. I would also recommend getting the video CD to practice on your computer. It will reinforce what to pick as you play and make the learning process very quick. It is also fun to play when not in Vegas. Here is the website:
http://www.bobdancer.com/
I now average about 1 per night of play and only play 5 cent and 25 cent machines normally. My biggest hit was pure luck with no skill involved. It was at the Orleans and it was a dealt royal on a 5 cent triple play machine for $4802. I was chasing a $700 5 cent royal on one of the triple lines and it dealt it to me. I hit the $700 about an hour later.