I tip every first drink so I wont have to wait as long for a second. for drinks...
every third beer bottle
every other draft beer
every mixed drink
I think this is very reasonable. It depends on the place though. If it's a place I frequent, I will tip more. If it's a happy hour special where stuff is ridiculously cheap, I'll tip on every drink. I don't think not tipping on every drink makes you a "cheap, miserable eff" at all. If I have change from a drink, I'll tip that every time, regardless of the drink.
I don't frequent coffee shops, so I don't know about tipping etiquette there. I I just order a coffee, how much am I supposed to tip?
I've also never worked in the service industry, so if I'm being an bad person without knowing it, please let me know.