At Bisley some years ago I had molded ones made for about 45 GBP. Tried them a couple of times, but they were a bit sweaty: their fit was too good. My ears could not breathe!
As a long-distance pax I always use noise-cancelling headphones until they start to hurt. Foam plugs are still probably the best easy solution as DropKnee says above. (In the cinema I usually have to make roll-ups out of tissue paper. Are young people so hard of hearing nowadays?)