Mounting Pictures and Mirrors in TC

I use small wood screws but not just the screws. First, I start out screwing in the screw where it's gonna be needed. Then I remove the screw and fill the hole with a toothpick dipped in wood glue, snapping off the toothpick where it is flush with the wall. Then I mount the item with the screw again. The toothpick fills the void and makes things very tight. I've never had to worry about over tightening a screw using this method. The glue keeps the screw from backing out. Many of my camper's hinge screws were constantly coming loose from the road vibrations until I removed the screw, stuffed a glue infused toothpick in and reassembled. So, this works on existing screws as well as anything new you are adding.