The main difficulty I find now with being vegan is eating out. It is easy enough at home or when visiting vegan friends, but eating out is often a problem, as animal products are in so many foods (and not just foods). Veganism is harder than vegetarianism, as the latter is becoming much more mainstream now: here in Britain almost all cafes, restaurants, etc., offer at least one vegetarian dish on the menu, and often more than one, but it is often hard to find a vegan dish.
Sometimes you find you can convert a vegetarian dish to a vegan one, e.g. a meat-free roast dinner can be made vegan if you leave out the Yorkshire pudding! Quite often though, I find I have to have a mixture of starters and side-dishes, rather than a full meal, which can be awkward. Eating out definitely involves more planning and consideration, than when I was an omnivore. The one exception to the rule is Asian restaurants, and particularly Indian and Japanese ones: there are usually a selection of delicious vegetable curries and accompaniments on the menu, so I always enjoy a trip to an Indian, Chinese or Japanese restaurant. Japanese food lends itself quite easily to veganism, through their use of tofu and edamame, which I am very fond of.
I also find it a pain trying to find vegan sandwiches, if I need a snack or light meal: once again, being vegetarian = easy, being vegan = often going without. Sometimes it is possible to find a falafel or roasted vegetable sandwich or wrap, for example (but it is not vegan if it has butter or mayonnaise in it). It's usually so hard trying to find a suitable sandwich, so I instead I will buy chips, crisps, nuts, fruit, salads, or vegetable samosas. I am also a fan of the pasta in sauce which comes ready to eat in a tub; that is quite often vegan. So eating out definitely involves more thought and effort (reading all the food labels, etc) but it is becoming easier and more natural to me now.