Making coasters using your knitted squares is probably one of the easiest ways to put them into use. There is nothing much left to do except to wash and dry them before use. Simple as that! But, here is a simple guide on knitting coasters for you, in case you run out of squares: Prepare your materials. Then, start by casting on 19 stitches with needle size 6/4mm. Make sure that you leave a 6-8-inch tail for later use. Knit across all the stitches with the knit stitch. Remember, you should come up with a garter stitch pattern when you do these steps. Next, you bind off all the stitches and secure the tail. Finally, weave in the tails and wash your coaster. You can also block it if you want your coaster to look neat and square.