Step 1
One full day before your event, hang the tablecloth on a clothesline. The heat from the sun will warm the plastic and gravity will pull out the creases. Do this for the full day for the best results.
Step 2
Use a hair dryer, on a low setting, to get the wrinkles out. Pass the hot air back and forth over the tablecloth and smooth it with your hand. Don't get the hair dryer too hot or too close to the tablecloth or you run the risk of melting a hole in it. This technique is especially helpful if you have an extra set of hands to gently pull the wrinkles out while you warm them with the hair dryer.
Step 3
Put the whole tablecloth in the dryer. If there are too many wrinkles for the hair dryer method, you can place the whole tablecloth in the dryer. Chose a low, delicate setting. You are only drying the tablecloth long enough to warm it up so that the wrinkles will fall out. If you leave it in the dryer too long, it will melt, and likely ruin your dryer in the process. You need to put it in for one-minute intervals once your dryer has warmed up. Take it out, shake the wrinkles out, and place it back on the table.
Step 4
Place a warm, damp towel on top of any especially difficult wrinkles and iron the towel. This will create steam to loosen the wrinkles. The towel will become very hot, so be careful not to burn yourself.