We do this with everything we hang---best thing ever! A tried and true method. Cut scrap paper to the size of the frame and mark the nail location on the paper. Using painter's tape, move the paper templates around the wall until satisfied. Then hammer the nail through the marks. Remove the paper template and hang!
Lizzie's Wallpapered IKEA Lack Table — Pretty City Things
A 20 dollar IKEA plain white coffee table...pick your wallpaper print, spray adhesive to get it to stick...apply mod podge and spray shellac over the wallpaper as a protective coating...and lastly, add decorative nails as a border...and BAM.