I don't consider myself a top competitor... but "top" competitor, maybe... only in the sense that I'm a bit top heavy.
I think the general answer depends on what kind of tournament you're preparing for. If you're about to participate in a traditional PAPA format (RIP) tournament, it's important to be able to achieve a moderate benchmark score... doesn't have to be the greatest score ever, but has to be good enough for midrange points on your ticket. For a best-score format, you need to throw caution to the wind and set up huge scoring opportunities... that might be a big multiball stack, or a quick path to a wizard mode, etc. On the other end of the spectrum is match-play, which is much more dynamic... depending on what other players do and what player number you are, you might need to plan on small safe points, or huge go-for-broke setups.
When I'm getting myself geared up for tournaments, I'll generally practice by setting score goals for myself on different machines, both for a game and for a ball. For example: Addams Family: 150M on a game... go. 50M on a single ball... go. Vary the goals until you feel you have a sense of how to achieve them with a high probability of success. Sometimes (often) the required approach is rather boring, because it's safe... in competition, safe is good.
Match play is especially interesting because you have to respond to changing situations on the fly. Say you're the last player of a 4 player group on ball 3 and need 20M to clinch one point, what do you do? Once you make that threshold, now you might need 50M to clinch the next point, what do you do? etc etc etc...
Practicing general techniques is always valuable. Knowing how to drop-catch, live-catch, post-pass, etc can only help you... those skills translate well to many games, especially of the solid-state and later eras. I wouldn't worry as much about practicing specific shots on specific games... being able to shoot the Lock shot on your home AFM with nearly 100% reliability is nice for pumping up the score against your family, but isn't really that helpful for playing at tournaments, because the AFM at the tournament is pretty much guaranteed to have different leveling, different flipper strength, possibly other weird conditions (different flipper rubbers? fatter post rubbers on the target shot? etc) ... in fact, in tournament situations where I have choice of game, I'll often intentionally avoid games that I own, because the tourney game is pretty likely to "behave" differently from my home game, and it takes me extra effort to un-learn the geometry of my home game that I'm very accustomed to.
None of this is easy, but that's a big part of the fun!