Most Europeans do not tip. In France, service is technically included (service compris). Never give 15% in restaurants b/c that would be 15% on top of included customary service. I usually give an extra euro or so for most meals...maybe a bit more if an expensive dinner or if the waiter is outstanding and/or helpful.

I'd consider giving the shuttle driver a few Euros if he helps with lots of bags, but he will not be expecting a tip.

Taxi fares are usually rounded up to a whole Euro, but I usually give euro or two if they help with bags (although they do charge extra for bags).