One thing I really enjoy doing is taking a mini-vacation. Since I only get 2 weeks of vacation a year, I'll take a weekend, buy a ticket out on Saturday morning, back on Sunday early afternoon.

It's nice because it lets me get out of town for a bit, stay at a nice hotel, and get both points for both airlines and hotels.

A couple important points are:
1. No internet/work. If you bring the internet with you, it won't feel like you're actually getting away. Bring a book or something similar. (And of course, only do this on a weekend where you can get away without doing any work).
2. Make sure you can find both a cheap flight and a cheap (good) hotel. If you stay at a poor hotel, it won't be fun. The good news is since you have a flight out on Saturday, you're likely to get an upgrade going out. It's a bit harder Sunday, but at least it's not the heaviest competition time.
3. If you have a long layover, make sure it's somewhere you'll have lounge access. I once had a 6 hour layover where the Admiral's Club was in a different terminal. Thankfully I was able to get to it, but going through security an extra couple times was a pain. The point is comfort and relaxation, and it can be hard if you're sitting in the terminal.
4. Go out and get a nice dinner. It's a bit weird eating alone, but it can be quite nice.