In no particular order:
1) Brown could and I think likely will improve.
2) Tatum could and I think likely will improve.
3) The young guys like Langford, GWill, RWill, Pritchard, Nesmith could all be better next year, at least some of them likely will.
4) Just better health overall. We were decimated this last year.
5) Better defensively by not playing two bigs, lessening the workload on the Jays, less dense schedule leading to increase in defensive effort, better communication.
6) Find a guy who can defense big wings (ex: Larry Nance).
7) Find one KNOCKDOWN shooting specialist.
8: Actually implement an offensive system (new coach will be big in this regard).
9) Better deep bench depth. No more Teague, Edwards, Semi level guys. Get competent deep bench veterans.
In short, A METRIC TON of ways. The c's won 2/3 rds of their games a year ago, the roster wasn't THAT different. I expect a fair bit of improvement even of they mostly run it back.