Just wondering if there's any how-to info out there about editing UIs.

I'm not new to programming and I'm fairly technically minded, but I haven't modded Bethesda UIs before, and I'd really like to try my hand at it since there's things I'd like to do that are mostly not drastic but variations on other UIs I've seen posted so far, where those other UIs have some things I like but some things I don't like.

Any help with general tips, places to start, specific tips, etc. would be appreciated, and I'm sure such a topic could be a good resource for other UI modders.