Those shotshell loaders you see in the magazines are nice to have, but they are not necessary if you just want to save money by reloading a box of shotshells occasionally. At least one company used to produce a small, hand reloading kit for shotshells that didn't require a press. Unfortunately those kits are no longer available new, and they are in high demand on the used market. But it is quite possible to build your own similar reloading kit out of stuff you may already have around the house.
Drill a 3/8 inch hole through the wood block. Place a fired shotshell hull over the hole and, using the nail as a punch, drive the spent primer out with the hammer. Repeat with the rest of the hulls.
Screw the pipe cap onto one end of the pipe nipple.
Place a new primer on the wood block, away from the hole. Set a hull over the primer, so that the primer enters the hole in the hull. Insert the pipe nipple into the hull, with the cap on the outside, and push down with the heel of your hand until the primer seats. Repeat with all of the hulls.
Trim the crimp off all of the hulls, using the scissors. Add a measured, proper powder charge to each hull.
Insert a plastic wad into each hull, over the powder. Push each one down firmly with the pipe nipple.
Pour a measured charge of shot into each hull, and top with a card wad. Push the card wad down firmly with the pipe nipple, then add a drop of wood glue to the centre of the wad, so it will spread to seal the perimeter of the wad. Allow 24 hours for the glue to dry.
For 20-gauge shells, use 1/4 inch pipe; for .410 use an interchangeable bit screwdriver with no bit. If you have a drill press, you can substantially upgrade your reloading kit by adding a roll-crimper head.
Always wear eye protection when reloading. Wash your hands after handling shot.