I have been using flatbed scanners for years to archive / edit / distribute / etc. I've managed to work out an efficient workflow for everything except the actual placement of the photo on the platen.
How do I keep the photo square? 
Ok, that may make me sound like an idiot, but so be it. Sometimes the most obvious solution is the easiest to overlook. I have this issue most prominently when scanning in bulk, i.e., more than one print on the platen at a time. Many of the prints will be slightly convex on the picture side (namely commercially developed, non-pro pics), so they do not sit perfectly flat, and due to a little static, not enough contact, tactile adhesion, and/or my bumbling paws, they will too often slide around and require adjustment.
It gets really aggravating when I keep moving the same print over and over and it keeps sliding out of square.
So when you are scanning at home/work, how do you avoid that issue?
Ok, that may make me sound like an idiot, but so be it. Sometimes the most obvious solution is the easiest to overlook. I have this issue most prominently when scanning in bulk, i.e., more than one print on the platen at a time. Many of the prints will be slightly convex on the picture side (namely commercially developed, non-pro pics), so they do not sit perfectly flat, and due to a little static, not enough contact, tactile adhesion, and/or my bumbling paws, they will too often slide around and require adjustment.
It gets really aggravating when I keep moving the same print over and over and it keeps sliding out of square.
So when you are scanning at home/work, how do you avoid that issue?