Many companies, online and offline, advertise that they make custom life-size cutouts for their customers. However, you can create your own if you have access to a good digital camera and a large format printer. And while large format printers are expensive to buy, sometimes you can gain access to one if you're at a university. Otherwise, you can simply take your file in to a copy store and have them print it for you for a fee.
Take your photo using a digital camera. Use the biggest file size setting that you can with the camera, and make sure the camera is at least an eight-megapixel one. You want to have as much resolution as possible so you can blow your image up to life size without suffering too much image degradation.
Plug your camera into your computer with a USB cable and import your photo into Adobe Photoshop. This works best with a fast computer (a.k.a. a computer with a lot of RAM). Otherwise the photo will take ages to load.
Select the "Crop" tool from the left-hand sidebar. Click and drag the tool across your image so that the selection just touches the head, feet, and shoulders. Make it as close as possible to the person in your photo. Double click on your selection to confirm the crop.
Select "Image" from the top menu of Adobe Photoshop and click on "Image Size" from the resulting popup menu.
Click on the "Height" field where the popup says "Document Size." Enter in the height of your person in inches. Enter "300" for the print resolution as well. The ideal print resolution for a colour image is 300 dpi (dots per inch), although you may still experience some image deterioration if you needed to blow your image up to life size.
Save your file.
Print your image using a large format printer. When the print preview screen comes up, make sure that the height of the printout is the same as that of your image. If you do not have access to one, save your file to a USB drive and take it in to a print shop to be printed.
Cut the image of your person out from the sheet of paper and put a thin layer of adhesive onto the back of it.
Lay the printout on foamboard and rub it to work out any wrinkles. Cut the foamboard around the image until you have a life-size cutout.
Taking a photo that is too large and having to shrink your image turns out better than taking one that is too small and having to expand it.