Black out shades for the nursery if you don't have them... We live at a pretty northern latitude and in the summer the kid would never sleep! There are some cheap ones that suction cup to the windows, which are great for travel too and won't break the bank.

We bought one color changing smart lightbulb for the nursery lamp and it was a great idea. You can turn it red and still be able to see when you come in at night, like a darkroom, while still being able to navigate the room and not trip over stuff.

Echoing the white noise machine. A cheap smart speaker (Google mini) can also be useful - you can adjust the volume from outside the room; there are ton of white noise podcasts, and if your kid likes music instead, you can start with that and switch to white noise.