Check out this cool little keychain that Sarah Lipoff posted over at Popsugar. Can you think of an easier, cheaper floating keychain than an eye screw and a wine cork? I sure can’t. This is about as basic as it gets.
The only assembly tip I can think of is to buy eye screws with the widest threads you can find. If they’re too fine they’ll be more apt to fall out over time. If you spend a lot of time on or near the water you should make a few of these floating keychains.
I’ll bet you $5 that you have an eye screw and a spare wine cork laying around somewhere…