I hike in and setup a base camp a lot, but I don't carry much with me on those day hikes from camp. A bit of food, FAK (1st aid kit), water, compass, map, GPS, maybe a light jacket. I generally don't do 10 miles on those day hikes though, probably closer to half of that.

I bring a small/cheap UL daypack I got from Wal-Mart. It's really just a stuff sack with a zipper and shoulder straps so I fill it with clothes or food when packing in and out and use it for my day hikes while I'm out there.

I'll add that the first one of those cheap daypacks busted a seam that was poorly sewn. I returned it with no problem and the 2nd one has held up fine so far. I also have a needle and thread and some Gorilla Tape in my FAK so I can make repairs if needed.