After you gather an assortment of gallery wall artwork, lay them out on a floor or large table. Arrange them in a way that suits you, keeping in mind that an organic arrangement is more interesting than a perfectly symmetrical one.
Unroll kraft paper and trace around each picture frame. Cut out these templates and hang them on the wall with painters tape, three to six inches apart. Make sure any heavy pieces are centered over wall studs. Mark where the hangers should go and hammer your nails through the kraft paper. Starting at the center of your arrangement, remove the paper and hang your pictures.