Ds was 6yo when he had his last grommets.
I gave him some options.
He was nil by mouth from 2am, so I asked him if he wanted a midnight feast, or to have a huge dinner at 10pm.
He chose a midnight feast, so I asked what he wanted to eat.
What we did in the end (all his choice) was I woke him at midnight. He went out on his scooter round the block, then he came back for hot chocolate and marmalade sandwiches.
He chooses what to take (pyjamas, and soft toy)
I told them he was nervous when we arrived and they asked the play therapist to come and talk to him.
One thing that I found is they don't want you to be there as the child wakes, I assume because of complications. They also don't go back to the same room they went to sleep in. So an earlier operation he woke in a strange room without mummy, and was very frightened. When he was 6yo, I was able to make him understand that when he came round he could ask for me and then they'd get me.
You need to check what the covid regulations are as last June (when he had appendicitis!) they weren't letting anyone else in recovery, so I was told he'd be brought back to me. In the end his op took so long, and there was no one else in recovery, and he always takes ages to come round, so they did fetch me, but I was told not to expect that.
I normally take a little present for him to open when he's recovering. In all fairness he's usually fairly out of it for 2-3 hours (he doesn't recover well) afterwards, so I'm not sure whether he really appreciates it!