If you've got a picture that could do with cleaning up, say to get rid of some unwanted people in the background or a pesky dust spot that was on the lens, then use the clone brush to pick a spot of the background, and paint (carefully
(you; 've got; a picture that could do with cleaning up) (a picture; could do; with cleaning up) (a pesky dust spot; was; on the lens)
you a picture a pesky dust spot
've got could do was
a picture that could do with cleaning up
with cleaning up
on the lens