I would submit that Ty Corbin needs to assess and apply these lessons learned last year:
1) Millsap and Jefferson as a frontcourt pairing DOES NOT work.
2) Hayward deserves minutes at SG over Bell, and is not an NBA SF.
3) CJ plays better when he starts and should probably be the starting 3. (Thanks davidcomposerguy)
4) Watson is the best distributor on the team now that AK is gone.
5) Evans needs consistent playing time *at the 3* even if it's 10 mins every 3rd game. He'll make good things happen. He routinely gets overpowered at the 4.
6) Harris needs to be coached out of his no-defense, shoot first mentality. He's developed bad habits he needs to break.
7) When Favors is staying out of foul trouble, keep him on the floor as much as he can handle. He pairs better with both Millsap and Jefferson than anyone else, and very possibly with Okur and Kanter as well, but we haven't seen enough of those 2 to know that for sure yet.
8) Millsap is serviceable as a starter, but excels as a 6th man type.
9) Get guys consistent minutes even if they're few and far between and make sure they know where they stand. The complaints out of the rookies just about every year is that they don't know why they play 20 minutes one game and then get DNPs for the next 4. They get yo-yoed around and it leads to frustration and loss of confidence.
10) Giving up open 3 pointers on defense is worse than giving up contested shots in the paint or wide open long 2s.
11) I know Clark and some others will dispute this, but if you're not going to play the rookies & other young guys, send them to the D-League on occasion to get playing time. The new rule change is especially conducive to sending guys down to get some playing time and calling them back if you need them.
I could probably think of more given more time, but those are the ones that stick out after the first preseason game.