Freebie foam ear plugs are great, and hygenic (very important). I have a pair of custom moulded ones (by Green Leopard
http://www.greenleopard.co.uk/) which I bought primarily for shooting, but use when doing sorts of other noisy things, such as cutting the grass, avoiding a nagging, and walk arounds. They are excellent, and a million times more comfortable than one size fits noone foam ones. At £40 they are wotrth the money. Only downers are that you have to wash them regularly, and there an awful lot of colours and combinations to chose from. If you fly a turbo-prop, particularly a Shed or something, you might try wearing them under your headset: it makes the world of difference.