This may help & interest you :
1) I started the game in April ; I played 0 practices in both offline and online at that moment and directly played official ITST matches
Result : 5 matchs lost in a row, 0 set scored (during april and may tournaments). But that helped me to progress in fact.
2) Even if I was still playing TS4 Xbox at the top level at that moment, I decided to begin serious practices on TE as I had more fun with that game.
I then began to play a lot of matches on the vanilla version (as the chat didn't exist at that moment) but never offline practice.
--> this gave me a normal level which allowed me to compete with the best players of this period (but not to beat them because of the mental, baseline skills and lack of experience).
3) I totally stopped Top spin 4 and focus on Llodra. Serve and volley was at the top, but return / baseline still sux a lot, so I wasn't able to get a lot of break opportunities (vs Robbin for instance).
So I decided to switch a bit for Nadal during 3 official tournaments to increase that and learn how to defend well.
I lost a lot of ITST points during the US tourney on Masters 1000, but I suddenly understood everything about baseline with the though matches I played. And I discovered a lot of little things too about positioning, end of course shots etc

I then came back to Llodra and practice a lot for US Open on online exhibitions to get a great baseline level with him.
And one day, I finally discovered I could play as well as anybody on the baseline with this apparently worst baseline character of the roster.
But at that moment, I had the feeling my level still failed a lot when I stopped practicing.
4) Now with time, I don't practice anymore. I can be absent for 4 or 5 days without touching the game, I just do 2 set warmup and I play at top level again.
The keys to be a great player ?
- Always taking risk, always aiming the lines
- Get a great service by practicing it with bad character (I increased a lot my service and my volley by playing with Nadal who has bad stats in these domains).
- Managing the cross court shots which are risky and touchy but often used by the top guys (Vmoe is the king of the cross courts !)
- In my opinion, get volleys skills.
- Work your mental : when you loose a match because of stupid errors, or because of a tie break lost whereas you dominated, or because of break points opportunities missed, remember that during your next match and tell yourself "this time I can't miss that opportunity !!".
In fact, talk to yourself during the match !