I always stick to the traditional 1 per drink unless it's a crazy drink.. maybe if they help you with some samples then a buck more or something but nothing crazy!
1 buck a beer
A tip is a "gratuity" or gift. 10-15% (more for groups) is the average range of tips. The location or business should have no bearing on what you 'decide' to tip... only the quality of the service should matter.
Thanks! Your answer is awaiting moderation.