That is a huge question! But a good one!
I just try to make the best choice I can under the circumstances. I travel alot so sometimes I find myself in truckstops trying to explain my vegan ethics! And I can honestly say I've met with some of the best responses and best service in said truckstops. People who were very genuinely curious and really wanted to help me out. I usually just get things like coffees, bottled drinks and sandwiches, most places are very willing to use a new knife (also aren't there food prep. guidelines about not using the same knives/cutting boards for vegetables, dairy and meat?). I avoid grill food because I am not going to stand there and ask them to clean the frkn grill on my behalf!
And I've met with the worst kind of scoffity scoff "we only serve rhinocerous pate served on a bed of fried baby birds and baked unicorn stuffed with lemmings" from fancier country restaurants in wine regions...which shall remain nameless.
When I'm at home I eat out in vegan places mainly unless I'm with omni friends. But I'm lucky because there are alot of places in Adelaide that at least cater to vegans and I like to give money to small businesses that are making a genuine effort to accommodate different diets, learn new things and understand ethics that they don't necessarily share.
With food shopping, I don't have alot of time so while I do try to buy from vegan/organic small business as much as possible, Foodland is a good everyday choice because they do have an excellent range of vegan goods in some of their stores. I also appreciate that recently Coles has started adding details about the vegetable/animal origin of additives to their labels on some of their home brand products. I picked up a packet of el cheapo garlic bread recently and was pleasantly surprised to read that the additives were all of vegetable origin (yay!!) but that it contained palm oil (ok, I will grant that it is good that they specified that the type of oil was palm oil...but my reaction was more like "you RUUUUIIIINNNNNED my DREEEAAAAAMMM!!)