VERY easy way. I've seen soaps tied with ribbons like a present with a bow on top - 1/4" wide ribbon bought by the spool at fabric stores (the after Christmas sales are best, it's 75% off then), or use textured fiber yarns for it.
The tag attaches to that. Go to WalMart or Target or Office Max, or even the Dollar Shop and look for clear contact paper. It's a roll of clear plastic with sticky on one side and a paper backing you peel off. A WIDE roll several feet long runs $10.The short roll at the office supplies store is longer but narrower and runs around $8.
Design your text in Word. Then size it to the shape you want. Put in a picture if you want. Copy/paste the design over and over in the Word document to fill the entire page up with little tags, leaving a bit of room between them (not much, just a space is fine). Print out the sheet.
Unroll the clear contact paper, laying it clear side down. Peel back the paper backing a bit and lay your page down on the plastic. Cut around the sheet with a scissors. If the labels need to be stiffer, lay the back of the sheet down on more plastic to coat the back side (if your soap is going to leave a grease spot on paper, do this step anyway). Use a small hole paper punch to make a hole in the corner and tie it on to the soap. You can get a real professional look this way. Make sure to smooth the plastic down firmly to avoid creases or bubbles. Cut each tag out once the plastic is smoothed.