Cheat sheet for a home theater (from someone who is working on it now):
Monoprice for cables and connectors. Keystone jacks are awesome, I didn't appreciate them until I ran them in my last two places. I'll never go back.
Get 4K capable, active cables even if you aren't using it today. The investment will save time and probably money in the future. *** Make sure you run them in the right orientation. There's a source and a destination for active cables: accuracy counts.
Run Cate5e minimum or Cat6 for the projector. If you are running one, then run two and 1Gbps is the minimum, Cat5 will disappoint if you want to run any UHD stuff in the future. The cost difference on the actual cable is really small, even if you leave it curled up in the wall. If you run into problems with the original run it will save lots of time and money to just use the second cable.
Conduit is awesome. Use it if its in the budget and the ceiling is open. I picked up some 2" conduit from home depot for like $12/10' and pvc glue for like $7 a can. Grab a bag of brackets and run it as much as you can. It will seriously make any future work super easy so that it doesn't matter what you want to run in the future. Add $5 for a length of mason's string and run 4 or 5 strings through the conduit so that you can pull in whatever you need in the future.
As mentioned, be sure to run an outlet to the ceiling.
If you are in doubt, buy extra cable and run it. I'm not expecting to run composite for my HT, but I have run it. Component too. 4k HDMI, check. CAT6 x2. Anything to prevent having to work inside drywall in the future. In ceiling/in wall work once the finishing is done is a major hassle.
Great scotch is great precisely because you drink it with great friends.