The best way to handle this is to have one person handle the splitting, and the other person gets to pick which one they want. Then the person splitting things tries their best to make them as even as possible.
and what, i hear you say, does one do if there are three siblings?
Sibling stuff is a fun intersection of I would give you a vital organ at risk of my own life and there will always be a risk I might pee on your face if I think it would be funny enough
This image is actually showing a complete lack of trust.