☆.A.
Best if they're not all the same size (like all 8x10's, etc).
What I do before I hang a photo collage is to lay it out on the floor first.
Try not to make it look too symmetrical.
Get similar family frames in different configurations and sizes.
Get a few of the ones that have 6 openings for 4x6 prints and sprinkle them through the collage.
If they are all the same size--I wouldn't do a collage.
I might think about O. frame with 4-6 opening.
Oh--and if you're going up the wall by stairs--keep them all at a horizontal line with the ceiling or floor (even if it's imagined). Ever see those photos going up-up-up along with the steps? Yeah...nah...don't do that!