Carry an umbrella. It rains a lot here, so if you commit one hand to an umbrella, you’re turning yourself into a one-handed person. Better to put on a rain jacket and have both hands free to do whatever.
Be grumpy. The Irish continually amaze us in how friendly, outgoing and helpful they are. Whether it’s resolving the language barrier between Irish English and American English; negotiating a one-lane road that has become an impromptu food trailer court at a combined children’s football camp and horse show; or simply explaining to an ignorant foreigner how to get along, the Irish maintain a cheerful equanimity that’s absolutely inspiring. Do yourself and everybody else a favor: get along, go along, and apologize when that doesn’t work out.
Look left while crossing the street. Good way to look like a dead tourist. Irish drivers will often stop, sometimes even in the middle of the block if you look like you’re about to cross the street, but you don’t want to trust your life to that driver being Irish. He might be another ignorant American in a rental car.

Speaking of that, I’ve decided to follow the Ted Lasso model of foreign relations: I can’t help being an ignorant foreigner, but I can help being a jerk about it. Better for me to leave my preconceptions at home, relax and join in the fun.