If you pull the yarn too tight when you crochet, whatever you're crocheting will curl up. If, when you set the object down, it immediately curls up into a tight roll, you may not be able to salvage it. However, you can save slight curling by a procedure known as blocking. Blocking is often associated with knitting, but all it does is help shape the finished garment. Blocking will help straighten out and shape an item, even if it curls up a little.
Things You'll Need
Finished crocheted item
Dry, clean towel
Surface to pin the object to, like an ironing board or a mattress
Stopper the drain of the sink, and partially fill it with room temperature water. Make it full enough to submerge the crocheted item.
Dip the item into the water and get it fully wet.
Pull the wet object out of the sink. Do not wring it out or twist it. Lay it on the towel, then roll it and the towel together.
Unroll the object from the towel, then lay it on your pinning surface. All you need is a surface that a pin can puncture and hold, that is big enough for the item to lay flat.
Pin the object to the board, pulling it into the desired shape as you pin. When you are done pinning, the object should appear to be the desired shape.
Leave the item to dry overnight. The next morning, unpin the item. It will have a nicer shape and much less curl, if any.
If you want, hand wash the item with a little detergent before you soak it in the water.
If you are blocking a wool item, be careful. Excessive handling while wet could cause the wool to felt, which would ruin your finish. Use minimal handling and rolling, if possible.