My answer to randomness is this - Generating seed phrase from dice - an easy, understandable method.

Basically, I took all the "seed phrase from dice" methods, and reworked them until I thought they were as easy to understand as possible.

Here's a chunk of the first page. Instructions/worksheet are towards the end.

This is the full guide. Feedback welcome.
https://bitcoinhandson.com/bip39-dice-worksheet.pdf