I would say that there is no sound formula for becoming a champion billiards player. If you have the skill and knowledge to play at the level required, the most important addition is on the mental side. Do not focus on what went wrong with any particular shot, acknowledge the miss and continue on with the match. I have seen many people on the verge of winning, only to get shaken up over a miss, unlucky leave or a good safety from the opponent, and never complete the match.
The mental aspect is definitely a bigger component than people realize. I played a game against Darren Appleton and was shaken at how I couldn't keep up. My mental state dropped and I failed on a simple run to give him the game, and it wasn't even a tournament with anything on the line.
Watch some videos of the pros and you'll see the top end guys don't have much difference in their actions and demeanor between being up 5 racks or down 5 racks. They treat and approach each shot the same.
Also, when you approach a high level tournament, defenitely practice, but don't go nuts, just stay warm. Focus on form and fluidity, you don't need to focus on a full table 85 degree cut. Keep it simple, medium distance and medium angle to practice ball control, aim and cue placement. Throw in a couple simple banks and kicks to get in a groove. If you start to just hit balls around without focus, walk away from the table and take a break.
These recommendations are not geographically based though. Just things I've picked up while playing the game. I hope this helps.