You can buy a seat for a swing fairly easily, but manufactured swing seats lack the charm and individuality that a handmade seat provides. If you have a little woodworking skill, you can make your own seat for a swing quickly and easily.
Select the type of wood you want to use for your swing seat. You generally want strong, sturdy wood that can support whoever intends to use the swing. Redwood and cedar are the most highly recommended, but oak and pine are fairly reliable, too.
Measure the length of wood you want for your swing. Any swing seat should be at least 43 cm (17 inches) long by 20 cm (8 inches) wide by 2.5 cm (1 inch) deep. A deeper swing will be sturdier but can be more difficult to work with while you make it.
Compare the expected length of the swing with the placement of the chain, rope or supporting device you intend to use with it. You want the two lengths to be compatible, and may need to adjust the dimensions of the board slightly to fit.
Use a saw to cut the board until it fits the proper length for your seat.
Apply sandpaper to the wood until the splinters have been sanded out and the surface is smooth and comfortable.
Drill four holes into the wood, one in each corner. The holes should be equidistant from each other and approximately 1 cm (3/8 inch) in size. You'll be running rope through these to balance the swing, so you should measure the placement of the holes carefully.
Run each end of a 1.2 m (4 foot) piece of nylon rope through the two right-side holes in the seat. Repeat the process with a second piece of nylon rope through the two left-side holes in the seat.
Measure the length you will need to hang the seat properly on the swing. It should be high enough off the ground so that whoever sits on it can just touch the ground with her toes.
Adjust the nylon rope to fit the length you require and tie the ends off with a thick knot. This will hold the rope in place on the seat.
Hang the seat on the swing.
If you have access to a manufactured swing seat, you may want to use it as a blueprint for the one you make. It makes measuring easier, and if it comes from an existing swing set whose seat you are replacing with the handmade seat, you can be sure that the one you make will fit.