My brother used to raise Mink, and he also was a pretty good trapper.
All the previous mentioned ideas are good, the fish or sardines, the only other suggestion he added was, you need to remove all human scent from your trap.
They have oils you can douse on the trap, after you boil it...
my brother boiled his in black walnuts. Then use gloves and once set, apply the oil...there is also oils to send the scent of a mating mink.
Hope this helps.
Oh, they will bite you, they have serious teeth. You will either have to shoot it, or knock it in the head. You cannot get close to them, regardless that they are small.