dead easy - The best roundabout advice I've heard was from Rick Steves who said to drive all the way around once before you pick your turn. One complete circle and then you'll know.
Not that dead easy ...yesterday coming off the A50 onto the M1 I managed a full circumnavigation, and still took the wrong exit. On the positive side, once on the M1 I was cruising at 140 kph. Try that in Oz! As far as tipping goes, I don't think I've tipped at all here in the UK yet. I did briefly consider tipping housekeeping this morning when they replaced my tea and coffee ...but the fact was I had had to leave a note to remind them. Yep - here in the UK some hotels don't replace your tea and coffee (Nespresso pods, admittedly) on a daily basis. My all time favourite was a place in Richmond, who I approached mid-week with a request for another small cake of soap. "Oh you want some more soap? Try Tesco in the high street.". No kidding. And no tipping.