The user can produce/create/generate clothing from energy or matter or drawing them from another dimension. They gain abilities related on the type of clothing worn, although this may be connected to their personal opinions, cultural connections, etc.
...and clads Gohan in training gi similar to Goku's.
Julie (Charmed) changing her clothes.
When Prince Adam (Masters of the Universe) wields his sword...
His clothes become armor and he becomes He-Man
Superman's (DC) costume in the New 52 is a biotech armor that allows him to materialize it on his body whenever he wants while wearing it.
While in his debut Hal Jordan's (DC Comics) Green Lantern costume was just another costume, it was later established that his and the other Lanterns costumes are constructs created by their rings while activated.
Erza's (Fairy Tail) Knight allows her to magically generate different armor and clothing from different dimensions.
Lucy Heartfilia (Fairy Tail) can transfer Celestial Powers to herself and gained a new dress based on each Zodiac Spirit.
Coordinator (Fairy Tail) can use Requip similar to Erza's.
Emi Yusa (The Devil is a Part-Timer!) materializes silver armor on her arms and legs.
The members of Frieza's race (Dragon Ball) are able to grow their own "bio-suits" and remove them at will.
Shinobi (Senran Kagura) can use their stored Yang Energy to manifest of each shinobi's idealized appearance.
Thuries (Valkyrie Crusade) can create clothes that bring happiness to all who wear them.