I think the main thing is just always having it available and I find that mine like raw fruit and veg more than cooked. I tend to offer it on a sharing platter in the middle of the table for meals, as I find they help themselves and eat more if they think that someone else might eat it first, rather than dishing it out individually on plates (where there is no pressure to eat it!).
So yesterday, for breakfast, my youngest (6) had half a melon (yes, I know, he really likes melon 😂) plus a banana. That was all he had as didn't want anything else - probably because he'd eaten half a bloody melon!
They get a choice of fruit/veg at snack time at school - so no idea what he had, but it would have been raw fruit or veg.
School dinner for lunch, which wouldn't have been super veg laden. I think yesterday jacket potato with cheese, probably some crudites on the side, cake/yoghurt for pud.
After school, they just sort of feast all afternoon and that can be on various things, but yesterday was (more) melon, an apple, a banana, a carrot.
For dinner, we had pasta bake and then I pop a big plate of chopped salad veg on the table for everyone to help themselves - baby tomatoes, sliced pepper, sliced cucumber, and mixed leaf salad with salad cream, plus some gherkins, which I guess also technically count as a veg.