IIRC, there are tutorials in the TPT wiki but no videos :)

Useful links:

https://powdertoy.co.uk/Wiki/W/Coding-tutorial.html - tutorial

https://powdertoy.co.uk/Discussions/Thread/View.html?Thread=18174 - FeynmanLogomaker's LET

^-^ Someone actually uses LET!

@FeynmanLogomaker (View Post)

 I always use(d) LET to get the base then screwed around with the properties for a bit. Now I've kind of moved on to just using my regular base. Sorry! XD