Even if your dress shirt is brand new, it's not necessarily wrinkle-free and ready to wear. Some shirts get creased at the store because of improper storage, sloppy folding or hanging on the rack. Ironing a new dress shirt is the best and fastest way to remove wrinkles. Depending on the heat setting you use, it's safe for most types of fabric. An iron may damage some types of fabric if it's too hot. Always use the lowest heat setting if you're ironing delicate garments.
Unbutton the shirt and lay it flat on an ironing board.
Mist the shirt thoroughly with water from a clean spray bottle. If the shirt is already damp from laundering, skip this step.
Plug in the iron and set it to the medium heat setting for most fabric types. If you're ironing a delicate fabric, such as silk or wool, use the low heat setting instead. Wait for several minutes for the iron to heat.
Fold up the shirt collar and run the iron along the underside of it from one side to the other. Flip the shirt over and iron the other side of the collar in the same way. If wrinkles pop up on the collar, push them down with the iron until they disappear.
Unbutton the shirt cuffs and press them down flat. Press the iron down on the inside of one cuff and iron from one end to the other. Iron around the buttons as the heat can damage them. Flip the cuff over and iron the other side. Repeat with the other cuff.
Place the shirt so the front faces up on the ironing board. Move the iron from the bottom of the shirt to the shoulder. Iron the area between the buttons, but don't iron the buttons themselves. If the shirt has a placket or front pocket, iron the underside of it first and press down on the front side with the tip of the iron.
Flip over the shirt so the back faces up. Run the iron from the shoulder area down to the bottom. Keep doing this until you've covered the whole back and the wrinkles are gone. If the shirt has a center box pleat, iron around it.
Lay one of the shirt sleeves flat on the board. Press the iron down on the shoulder of the shirt and slowly run it down the sleeve to the cuff. Flip the sleeve over and repeat. Lay the other sleeve flat and iron it in the same way.
Allow the shirt to dry fully before wearing it.