I use nothing but foam earplugs and have been doing so for many years. It is a lot easier to insert them if you lick them a little before inserting them into your ear. Or (if you are not into licking dirty earplugs) you can moisten your ear with a little water or hand lotion before inserting the plugs.
Whenever I remove my foam EAR-brand earplugs they stay somewhat compressed, so I always place them in a plastic case and put the case on a hot engine (if I am riding one of my IC motorcycles) or place them in a sunny location. Then they will get hot and expand back into their original shape. Once that happens, you want to cool them and, once cool, that will make them roll up easier and tighter and stay that way longer as they are inserted into your ear. However, most other disposable foam earplugs, such as the Hearos-brand, (which I also like) do not need this treatment, although they do typically insert much easier when lubricated slightly.