I always check whether my flight is on a Boeing and tend to avoid them—better safe than sorry! Fortunately, in Europe, most carriers primarily use Airbus, which simplifies things. Essentially, it boils down to avoiding Ryanair, and there are plenty of other good reasons for avoiding Ryanair.
My favorite thing to avoid Ryanair is, despit being most used in Europe, they never had a single deadly crash. not even once. So it's great reason to avoid actually. too safe? I prefer less safe airlines like germanwings? or maybe any other with actual crash history. Also some leg room is more important than my safety. you know?