Tobberoth

Rember to add SAS modules and activate them, either by holding F or pressing T. For a general liftoff, you can just toggle SAS on with T and leave it on until you want to start thrusting horizontally. As long as you have enough SAS for your rockets weight and speed etc, you'll fly more or less completely straight up. After that you can turn it off, but still use it from time to time to stabilize. Do your adjustments, then hold F until it calms down.