Some times, it's easier to simply "google it".
http://lmgtfy.com/?q=How+to+manipulate+photos+tutorial
Also also, avoid grabbing until AFTER the first hit, looks sloppy if you have to grab during the manip, or to get the first hit.
It makes it look like you need to grab in order to get Uke where you need him, instead of being able to do it naturally.
on the other hand, making grab manips look good is super hard and you're the coolest kid around if you do it