I kind of estimate my salads. I usually make my salad with a similar amount of veggies each time. The first time I make a new salad combination, I weigh and calculate one large serving then make a new entry in my food log. Each time I have that same salad, I will use the same bowl and eyeball a similar serving size. It's not an exact measurement but it is pretty close, and much easier than calculating it each time

I always measure dressing, tomatoes and any higher calorie ingredient like fruit or nuts, separately as they add up much faster than low calorie veggies.