It's a shame to throw beautiful stamps away. So I turned them into note cards by pasting them to blank cards that I bought for 15 cent each in Handyworks, Dalkey. Either cut the stamps from the envelope or soak them off in a little water.
Take your blank cards
Cut the stamp off the envelope.
Mark the centre of the card - the stamp is so small that it's very noticeable if you stick it off-centre.
Paint glue on the back of the stamp - use glue sparingly as you don't want to distort the stamps.
Ta-da! I think they make very elegant, interesting and cost-effective note cards.
If you buy stamps from a collectors' then your cards will have an historical dimension too!