One thing I've found helpful is that you can find out the current UV levels for your location, e.g. https://www.arpansa.gov.au/our-services/monitoring/ultraviol...

I live in the antipodes (near the ozone hole), am fair skinned, burn easily, and have had low vitamin d levels when I've had them checked.

I cover up or am very careful with sunscreen when the UV is high, then try to do the opposite (no sunscreen, lots of exposure) when UV is at lower levels. The idea is to generate vitamin d at safer times while avoiding skin cancer.

I also supplement with vitamin d pills.