2tsp - normal level of carbonation
3tsp - good level of carbonation, ideal if you are decanting before serving
4tsp - high level of carbonation for lagers - will need a few hours in the fridge before opening.
was watching rory mcgrath last night and he was bottling, but when he added the priming sugars to the bottle and then added the beer, he then shook the bottle to dissolve the sugars.