I think it’s like any game:
- figure out what key factors are needed to win at a high level,
- make sure to have those factors within required thresholds,
- execute and win. (or at least perform within an overall level)
OR
be one of the freak anomalies who can win despite not fitting the mold.
Also, I assume you are talking about becoming good with a character as opposed to consistently placing high in tournaments.
So, for Street Fighter HDR, let’s look at the “key factors”.
Dexterity.
Matchup Knowledge.
Focus.
Execution.
Find out who the top players are with your character in HDR and ST.
Find and download top level videos with your character piloted by top level players.
Make sure you can consistently physically execute ALL the moves (combos, strings, set-ups, etc.) that these top players can perform with these characters.
Make a list of the most complex moves, talk to a top player (who is at the level you are targeting) and confirm these are all the moves needed, see if you can do all the final list of moves.
If you cannot, then practice (or whatever it takes) until you can.
If you cannot even after practice, then you cannot expect to be as good as them.
Find out who the top players are with a second character in HDR and ST.
Find and download all the videos you can with your character and their character being piloted by top players.
Watch a video, and check how many times during the match your character does something that did not seem like the exact choice you would have made.
Check EVERY second. Whether that means your character edged back or ate a cross-up or executed a ToD.
If you cannot account for EVERY move at every second of these top players make (even their mistakes), then your matchup knowledge is not on par with theirs.
If your matchup knowledge is not on par with theirs, then you need to build up your matchup knowledge.
Buy Yoga Book Hyper, study matchup videos and compile flowcharts for different scenarios (how to start round, what to do after throw, what to do to deliver damage, how opponent delivers damage, spacing, normals used and set-up, etc.; all matchup specific), read posts by top players, and start playing in Quarter Rooms or with top players, etc.
If you cannot follow the moves of top players, then you cannot expect to be as good as them.
Next comes focus.
If you are not playing to win, then you are a lot less likely to win.
So make sure your focus is on target.
Playing with a high quality of opponents often pushes competitive players to maintain a high focus.
If your focus is not on target, then you cannot expect to bring your dexterity and matchup knowledge to bear.
Execute.
All the above really won’t teach you how to be a better player in itself.
But it WILL help you figure out what you are missing.