Launder your shirt according to the care tag stitched into the inside of the shirt.
Dry the shirt using the heat cycle recommended on the care tag. To combat wrinkling and static buildup during drying, use a fabric softener sheet.
Hang the dried shirt on a towel hook or rack in your bathroom. Run a hot bath, and close all windows and doors so that steam begins to accumulate. Let the water run until the bath is at least halfway full.
Allow the shirt to hang in the steam-filled bathroom. The humidity will smooth all wrinkles as it hangs.
Remove the shirt after 10 to 15 minutes. Hang it where it will not be crowded by other garments.