This month I'm going over how I use reamping to dial in a guitar tone I like in a very measured and controllable way.
1. Remember to use the guitar you are going to use for the application, or something very similiar.
2. Use a microphone to monitor the amp sound. What you'll hear back in stage monitors and what the audience will hear is the sound of your amp, through a mircrophone. A Shure SM57 is a safe bet.
3. Get your amp off the floor! Low end will seem particularly pronounced coming through the floor. You can eliminate that heavy bass translation by simpling putting your amp/cab in a stand or on a chair.
4. Play riffs and ideas that really show you what you want to hear. Palm mutes, 6 string chords and pinch harmonics are good benchmarks.