if theyre low value, I line up several coins on a strip of paper (or tin foil) and fold it over so that they're covered, I then fold the ends of the strip over so they don't slide out the side. Then I tape the whole thing to a piece of cardboard which I then put in an envelope. put lots of tape over the cardboard bit so coins that do somehow escape the paper don't get far.
Wrap each coin individually into thin Alu-foil, organize them on a piece of cardboard and stick to it with wide adhesive tape. When done, add another, similar, piece of cardboard on top and into the envelope.