Another thing you'll want to see is where your camera is focusing - it doesn't always automatically focus on exactly what you want it to. My camera shows this with little brackets that appear at the actual point(s) where my shot is in focus. If it doesn't automatically focus where you want it to, let go of the shutter button and press it down halfway again. If that still doesn't work, let it go try moving the camera into a slightly different position before pressing it down again.
NOTE: If you can't get these little brackets to display, reference your user manual to see if you have that function, then follow the instructions to enable it.
Once you are in focus, press the shutter button the remainder of the way down to take your picture. Try to be as still as possible. Use the review button to see if it turned out the way you wanted it to. If not, try again!
NOTE: These instructions about how to focus can be applied even when you aren't using macro.
Something important to note: different cameras have different abilities when it comes to Macro. For example, your camera's Macro setting may allow you to focus on a subject less than an inch from your camera. My camera will not focus that closely - I have to hold my camera a few inches away from my subject. The best thing to do is play around with your camera and see what it can do.
Finally, don't be afraid to pull out the user manual that came with your camera - it should have a good description of how to use the Macro function. Or you can just go here. :)
You'll probably be surprised at the kind of pictures you can take when you actually make the time to get to know what your camera's features are. If you don't believe me, read Angela's testimonial!