If your watch straps are too loose, there are a few things you can do to make them tighter. First, try adjusting the buckle. Most buckles have multiple holes that you can move the strap through to adjust the fit. If that doesn't work, you can also try trimming the excess strap material with scissors. Be careful not to cut too much off, as you won't be able to adjust it if it's too short. Finally, if neither of those options works, you can always buy new watch straps that are the right size for you.