I'm trying to take some self-portraits, but?

Can anyone help me? I have a Nikon D40 and I want to practise by taking some self-portraits. I had some ideas in mind of what I could do. The thing is, when I set up my camera and put it on a timer, it doesn't take because it's got nothing to focus on, since it's pointing at a plain white wall… What do I do? It will only take a photo if there's something to focus on, when obviously it can't be me because I have to set the camera up before I step back into position. I'm so confused, is there anything I can do? I've tried every single setting and none of them will do it.

Find a quick removing item to put in place of where you intend to pose yourself. I've used flower vases, lamps and shades etc. And then I'll go through the movements to get my ten second timing down so I can shoot. You can always find a quick object than can be removed in a hurry. How about a head sized balloon on a small weight… Pop the balloon and smile!

Get one of these http://www.bhphotovideo.com/...ntrol.html and you can trip the shutter from where you are sitting.

Get yourself a cheap infrared remote like this:
http://cgi.ebay.com/...2591wt_907

It should work just fine. When you're using a remote like this, then the camera will automatically autofocus before taking a photo, unlike the self-timer.

Then the next problem will be to pose in a way so that the camera focuses right on your eyes.
It helps to have an UV filter on the lens (a flat surface) because then you can see your reflection on it. If it is perfectly plane to the lens, then you focus on your eye when you see your eye in the middle of it.

Get a sticky note or one of those sticky bookmarks or tape something where you want your focus point to be and use that to frame and to focus.

If you do this kind of thing often, a dummy might be useful.

All the other suggestions will work, but here is a much easier way. It is called reverse focus. Place a mark (a piece of tape or whatever) where you will stand. Take your camera with you, and focus back on the tripod head where you will have the camera mounted. If not using a tripod, focus on whatever you are using to support the camera. When you have focus, PUT THE LENS IN MANUAL FOCUS so it will not change or have to achieve focus before firing the shutter. It is also best to use a smaller aperture such as f8 to give you more depth of field and a little more "cushion" for any focus error. Then when you remount your camera and go stand in your spot, it will already be correctly focused.

A remote shutter release is also very handy in these situations, much better than trying to run into place and "get settled" all within ten seconds. I have never understood why the camera manufacturers do not put much longer timer options on the camera.