I sign all my prints with my initials. For something open edition I generally put the title on the left and initials on the right under the image. For limited edition it would be the number left, title middle, initials right. Then I mount to incorporate that in the image area.
Signing mounts seems to be a trend for some artists. Since I remount and reframe almost everything I buy this means I lose the signature.
(I like really wide mounts - lots of space around the art - and the same mount colour on all my collection just because I like high white)