Whats the correct way to animate props into a character model? I've been struggling to find the right words to ask the question i'm trying to ask but i'll try and explain the best i can.

I'm making a character for a game and in the action editor I have a Walk cycle, a run cycle, and a few other animations. I need to animate the character holding up a sign, whats the correct/best way to do this?

Do i need to animate the sign separately  and put them on top of each other in unity, or combine the meshes and animate them together or some other way that I cant think of?

Any help really appreciated.

Thanks!
I would recommend adding an empty object as a child of the hand bone. This will allow you to preposition the empty to account for object size etc. You can then add a constraint to your prop that follows the empty. You can keyframe the influence of that constraint to set the object down or to pick it up.