Hey, no tattoos on the preggo pic?
Anyways, just chimed in to throw another -unwanted- tip.
You can use the mask tools to warp and bend tattoos, so they follow the shape of the underneath skin. (I'm assuming you're using photoshop or similar)
For example:
if you want to put a tribal tatto on a leg, select the tattoo layer ( with the Move Tool, usually "V" on photoshop), and right-click.
You'll get a distort option that lets you warp the image. It's kinda tricky, but once you get it, it lets you "fake" perspectives or shape.
Alternatively, you can cut and distort (I find this much reliable than the "distort" option above)
For example:
let's say you want to make a tramp stamp.
Use the rectangular marquee tool (usually "M" on PS), and "mark" 1/3rd of the stamp. So it'll be like _ _ _
Distort one side of (let's say up) the selection by dragging the little node boxes. Leave the middle 2/3 of the stamp as is. Then select 3/3rd portion, doing the same than first selection, but this time distort up the other side.
It'll give you shape like \ _ / .
It is a bit crude, but of course you can cut more (let's say 1/5 times) with slight different dregrees, to simulate the curvature.
For text (like "sissy" or that kind of stuff) is easier, as there's is a outstraight text-distortion tool at teh top of the screen. And you can also distort text by selecting the text layer with "move tool", just like explained above.