I have tried many methods and I now simply use the "Burst" carbonation method described by Marshall over at Brulosophy. Simply put:
1. Get beer really cold (32-40 degrees)
2. connect gas as usual and set PSI to 30 PSI
3. Wait 18-24 hours.
4. Vent headspace, reduce to serving , and check carb level.
5. As long as it's close, you should have perfectly carbed beer by leaving it cold and at serving PSI within 2-3 days.