Definitely make arrangements for airport pickup ahead of time. Just flag down a red plate taxi, negotiate a rate and you're good to go for local rides. I don't always tip if I've negotiated a rate, but will round up if I'm happy. If I'm by myself for short rides, say to get some supplies at Shamrock, I'll use a route taxi, which is a fixed price, not sure what it is this year, ? 150J. At a bar, just tip like you would at home.