[kibwen]

At this point you can just play odds and evens: one person picks odd, the other picks even, they both hold up either one or two fingers behind their back, reveal them at the same time, then sum the result. This prevents the randomness from being in any one actor's control. If you're worried that your brain's RNG can be gamed, then put an odd-denominated coin in one hand and an even-denominated coin in another, and mix them up so that even you don't know which hand has which.

[InitialLastName]

I can feel the difference between denominations of my local coins no problem. What you need are a pair of coins with an odd year imprint and an even year imprint.

[mewpmewp2]

We still need a study then to confirm that when people try to mix the coins in their hands like that, it would be random enough. And that would take another year...