Yes I do- some vegetables have more calories than others. Like onion and lettuce are VERY low in calories but cauliflower is actually pretty high in calories (and so yummy).
I count the ones I know have more calories -- mostly the starchy ones like corn and white and sweet potatoes. I don't count watery veggies like lettuce and cucumbers and zucchini.
However, I do plan for a "cushion" of 100 to 200 calories that I figure counts for those veggies that I eat throughout the day that I know I'm not counting. I weigh EVERYTHING else, so it's nice to not have to weigh out those voluminous veggies that I'm just eating to feel more full.
I think an ENTIRE cucumber is like 30 calories. I spend enough time weighing and packing my lunch without weighing out 15 calories of cucumber.
I count up veggies that get eaten as veggies, but not the ones that get eaten as garnish. Like, when I roast asparagus and eat it with/as a meal I count it, but when I put a slice of onion on my tuna sandwich I don't count the onion. Like another poster, I leave myself a small "other veggie" cushion of about 100 calories and I think it would be hard to put 100 calories worth of onion on a sandwich. I write it down but I don't measure the slice or anything.