Set your ironing board horizontally next to the end of the dining room or kitchen table (move the chairs first). Place a sheet on the floor in front of the ironing board on the same side where you will be standing. Wipe down the sole plate of your iron if it is dirty. Set the iron on the correct temperature that is suitable for the tablecloth's fabric.
Lay the edge of the tablecloth upside down on the ironing board and let the rest gather on top of the clean sheet at your feet. If you don't iron the tablecloth from the backside or if the fabric is delicate, use a pressing cloth to act as a buffer between the tablecloth and iron to prevent possible burns, damage and stains from the iron.
Mist the tablecloth with water. Iron it in the direction of the tablecloth's grain, going back and forth. When you are done ironing the first section, set your iron upright next to the tablecloth on the ironing board.
Slide the ironed area of the tablecloth onto the table and iron the next section. If the tablecloth starts to hang over the table and is about to touch the floor, roll it up rather than folding it or let it drop on the floor. After you are done ironing, the tablecloth is already on your table, and only needs a bit of adjusting to make it straight.