A trick for hanging photo collections: Lay out your arrangement. Flip frames over. Lay waxed paper on top of frames. Mark hanger/nail spot on waxed paper. Flip waxed paper over and tape to wall, nail into wall where indicated. Tear down waxed paper. Hang photos.
Good old Martha taught us that rather than buying those ridiculously expensive anti-slip mats for a rug, just turn it over and run a few lines of acrylic-latex caulk every 6 inches or so. Let dry and flip over and your rug wont be going anywhere! So easy.