Lukas Fassler has published a new build, a DIY PWM dimmer for LED lighting:
I have recently moved to a new apartment and was looking for a PWM dimmer to control some 12V LED strips. I thought that should be easy enough nowadays but it proved more difficult than I thought. All I found either didn’t meet my requirements, were uggly or expensive. So I decided to build my own, tailor-made to my needs.
Project info at Soldernerd site.