This is how I work for improving game(especially postflop play)

Situation:
CO open 3bb and BTN 3bet 9bb.
BTN 3bet range: JJ+,AQs+,A2s-A5s,AKo,ATo,KJo
CO calling vs 3bet range: 88-JJ,AQs,KJs+,QJs,AQo,KQo

Flop: TcKh3c
Equity: CO 44.29%, BTN 55.71%

CO
Check/Raise: TT,QJs,AcQc [8c] 14.3%
Check/Call: JJ,KJs+,KQo [21c] 37.5%
Check/Fold: 88-99,AQo,AhQh,AsQs,AdQd [27c] 48.2%

BTN
Value bet: AA,AKs,AKo [18c] 25.7%
Bluff/draw bet: AQs,Ac4c,Ac3c,Ac2c,Ac5c [7c] 10%
Check-back : JJ-KK,ATo,KJo,Ah5h,As5s,Ad4d,Ah4h,As4s,Ad3d,Ah3h,As3s,Ad2d,Ah2h,As2s,Ad5d [45c] 64.3%

• My CO calling vs BTN 3bet range might be too tight, but since im not good at postflop, i prefer to use tight range. in the reality, when I 3bet against CO from BTN, I usually assume that CO has wider calling range than my range.

I know it might be far away from perfect. I am just wondering that whether i am on the right track or not.
If it is good way to improve my postflop game, i would do this as many as possible.

any suggestion plz?? thanks a lot.