Always. Most of the food I consume is not processed, but I do buy some processed stuff.
I always check for Aspartame, as this is something I avoid. Artificial sweetener #951. Often added to "no sugar" products.
Hydrogenated oils, also make an effort to avoid these.
I don't trust "fungus protein" aka Myco-Protein, which is marketed to vegans, by people perpetuating the myth that humans need a lot of it. I've been a vegan for several years now and high protein products simply don't satisfy my hunger. After enough energy, there is a fiber requirement for the vegan gut bacteria. However I'm not against natural fungus products in moderation, such as cooked mushrooms.
Along this line, once in a while I'll buy some vegan sausages or something, just for the sake of indulgence in memory of things I used to eat. Of course I look at the ingredients. Usually (as was recently) the products are expensive, loaded with isolated plant proteins and, although tasting good, don't really satisfy unless I basically eat the packet.