I carry 2 tire levers, (metal ones), one tube with a 68 mm stem so it will fit most rims, one glueless patch kit (park tools), small multitool, one shimano chain link pin, and one shifter cable long enough to reach the rear derailer. All this fits in a small seat bag. I also carry a frame pump. Nothing worse then being 60 miles from home and having a broken shifter cable, chain, etc.
For tires I like Bontrager Race Lite Hardcase. They are heavy as sin ~ 340 grams per tire, but I usually ride 5000 miles on a set and never flat.
Cheers
Eric