Set up the ironing board so that you have plenty of room to work on all sides of it. Plug in the iron, and adjust it to the cotton setting (high heat). If the garment you’re ironing is made of cotton mixed with other fibers, it should probably be ironed on medium heat; always check the garment labeling if in doubt.
Stretch the garment flat across the ironing board, smoothing out as many wrinkles with your hand as possible. This helps keep you from actually ironing wrinkles into the item instead of out of it.
Start ironing from the collar if you’re ironing a shirt or from the waist if you’re pressing pants. Whether you start at the collar or the bottom to iron a dress is purely a matter of personal preference. Smooth any rounded or shaped portions of the garment over the rounded point on the ironing board so that you can iron flat across the fabric; flat portions of the garment can be pressed on the flat, wide middle portion of the ironing board.
Pay careful attention to how the garment is shaped or stitched together, and run the iron smoothly over one portion or panel of the garment at a time. For example, you might start with the collar of a shirt, then move on to the sleeves, then do the back, then the front and finally the sides.
Keep the iron in constant motion when it’s in contact with cotton clothing. You don't have to move it very fast, but if you allow the iron to sit or rest on the cotton for any length of time it may produce a permanent scorch mark.
Hang the cotton garment immediately after you finish pressing it. Don’t wear it until it is fully cool and dry, as the heated fibers are prone to wrinkling once again if given the chance. Make sure to fasten all closures--buttons, zippers, and hook and loop fasteners--to help ensure that the garment maintains its proper shape while hanging.