Just received mine today. Its definitely too big to put on the side of my finger. Unless you have a thick thumb or pinky, I got thin boney fingers though. On top of the hand is kind of odd cause then you’d have to turn your hand upside down to pickup stuff.
So I was thinking along the side edge of the hand beneath where the pinky finger connects but that skin is pretty thick plus if you ever instinctively slammed your hand down on something or absorbed a hit that’d be a risk to break the capsule.
So now I’m thinking it would be good on the bottom edge of my wrist right before my hand. Skin is thin there, its relatively close to tendons and nerves (but not on top of them) which might help with feeling magnetic fields. Plus its still a convenient location to grab stuff. Thats all I could think of.