RNG is a weird topic and it's too advanced for this thread. But dice and coin flips are not completely random all the time.
Ok, for fun there is also a "pattern" way of key generation: https://youtu.be/0Ug4YBEyRFQ
This is like brain wallet, but use logos, patterns, symbols and other visual ideas
Such pattern keys could be used for small gifts and funny presents to others.