At both the school's my DC attended, parents arranged a party on the last day, which involved rounders and party games, outside. (One school at a local cricket club, the other on the school playing field.) Only one did hoodies, but I think perhaps that was less of a thing a few years ago, so maybe the other school does them, now.
Dressing up on the last day was a big tradition for one of the schools.
There was a leavers assembly for both. One more formal than the other. The less formal one included sketches done by the children, in which they lampooned the teachers. They were very funny.
One school has a evening big prize giving which parents attend, and the other the prizes are given at a daytime assembly, which parents don't attend. I think most, if not all, year 6s get a prize of some sort, at both.
Both had a residential towards the end of year 6.
And both did that shirt writing thing. In one school, children were given cheap tshirts to write on, as the uniform is patterned, so not really suitable.
They loved all these things, I think.
I never really understand the fashion for a prom at that age, although some schools local to us have them, so it must be something the children want. But then, my one DD who is old enough to have had a year 11 prom wasn't all that excited about that, and it wasn't the big deal at her school that it seems to be at some schools, judging from MN. No one arranged limousines or other exotic transport, for example.