One of the great tips I remember is that your arm and elbow should be around 90 degrees when your hands are in the 9-3 position. I've always found that comfortable.
Current: 2008 BMW M3 Sparkling Graphite/Bamboo Beige/6MT. 1999 BMW M3 Techno Violet/Dove/5MT. Next: 2017 BMW M3 CP