Re LED's, I'm using these for the interior:
https://www.banggood.com/T10-194-168-W5W-COB-8SMD-SILICA-Car-LED-Door-License-Light-Bulb-p-1029639.html
and these for the frunk/trunk:
https://www.banggood.com/36-39-42mm-12SMD-4014-LED-Canbus-Error-Free-Festoon-Interior-Light-Bulb-White-p-1046691.html
...but anything similar would work just as well. I've not had to do any electrical work to make them work, and it's not burst into flames yet... touch wood
Re ambient lighting, yeah I was thinking of doing something similar with a string of this I have, should give a nice subtle glow, just not got round to it yet...
https://www.aliexpress.com/item/5M-Car-lights-Driving-at-night-Ambient-Light-EL-cold-light-line-DIY-decorative-dashboard-with/32750240269.html?spm=a2g0s.9042311.0.0.RUycsa
I also bought a set of Golf footwell lights and made a holder for them out of some old perspex, then fitted them up in the footwells wired in to go on when the doors open for a brighter footwell lighting...
https://www.aliexpress.com/item/LED-Footwell-Light-Interior-Foot-Lamp-Connection-Cable-Harness-For-VW-Golf-Jetta-Passat-A4-A6/32830930397.html
And if you don't already have the variable wipers knob on your dash, this is quite a handy cheap mod :
http://986forum.com/forums/diy-project-guides/60548-adding-variable-intermittent-wipers-early-box-easy-way.html