I've done the napkin thing plenty of times. It's fine if there's no other option, but I always have problems with them leaking certain frequencies, as well as blocking certain frequencies, more than others (your crumbled napkin chunk may vary).
The rollable foam EAR-type plugs are great for blocking loud noise, but cut way too much high-end from music. They make everything sound way too muffled.
The best I've tried are the Hearos rubber tree-type plugs. I believe they are made or designed by Etymotic and marketed by another company as Hearos, so the Etymotic plugs should be almost identical. They do a good job of cutting enough volume to avoid damage, while maintaining a balanced frequency range. They allow you to hear all of the high end and vocals that some of the foam plugs or napkins cut out. They take a bit of time to get accustomed to, but they are worth checking out if you go to a lot of rock shows.
The rollable foam EAR-type plugs are great for blocking loud noise, but cut way too much high-end from music. They make everything sound way too muffled.
The best I've tried are the Hearos rubber tree-type plugs. I believe they are made or designed by Etymotic and marketed by another company as Hearos, so the Etymotic plugs should be almost identical. They do a good job of cutting enough volume to avoid damage, while maintaining a balanced frequency range. They allow you to hear all of the high end and vocals that some of the foam plugs or napkins cut out. They take a bit of time to get accustomed to, but they are worth checking out if you go to a lot of rock shows.