Instead of buying ear plugs from a store, it's possible to make your own. This needn't be expensive. Use the plugs to block noise or water and, most importantly, to protect the ears.
Roll two pieces of cotton wool big enough to fit inside your ears into a cone shape.
Coat the outsides of the cotton wool in petroleum jelly. If you're using these to block out noise, use the petroleum jelly sparingly. If using for swimming and water protection, apply more liberally. Because the jelly is oil-based, it will repel any water that comes into contact with your ears.
Fit the cone shape of the plug into each ear. Press gently, allowing the leftover cotton wool to fit the shape of your inner ear. The better the fit, the greater the protection.
Use scissors to trim any excess cotton wool material to make the plugs look neat and compact within the ear.
If you plan to use the earplugs more than once, mark each "left" or "right" as they're moulded to each ear.
Reusing these ear plugs without disinfecting or for extended periods of time can cause ear infections. Clean plugs regularly or make new pairs as needed. Never force the plugs too far into the ear canal. It can cause a blockage of natural ear wax or make the plug difficult to remove.