Here are a few things that I did that have made flight simulating a lot more fun:
1. I started flying all the legs for my virtual airline VFR, and in the King Air. Here's a shameless plug: http://tradewind.org
Good, easy-going folks (who don't care if I fly their legs VFR and in the King Air), and a fun route system. Check it out if you are looking for a VA.
2. Other than the VA flying, I've restricted myself completely to the piston fleet. While FS
has extremely simplistic models for the turbine aircraft, the piston airplanes are fairly close to the real thing (especially the Cessnas).
3. In those piston airplanes, I adhere to the checklists for operation.
4. Plan my flights on airways, and I navigate by using airways--GPS coupled to the autopilot is considered cheating. Use of the autopilot is allowed, but it is restricted only to heading and altitude hold.
5. I keep a nav log, and use a real nav log form. I keep track of fuel burn, true airspeed, ground speed, and ETA/ATAs.
6. Autopilot-coupled approaches are out. In fact, the use of the autopilot is banned inside the IAF.
7. Use of the auto-tune function is also not allowed. I have to record the frequencies and tune them myself.
8. And using these methods, I fly to as many interesting places that I can.
Sure, flying this way is a lot more work, but it's a lot closer to reality, and makes simulating anything but boring.