I found this idea on Navigating the Mothership and thought it was so cute and easy to do, and definitly had to save it to the bookmarks.
Crib Rail Protector Tutorial
Supplies: 2 yards fleece fabric and decent scissors. That's it. Seriously.
Step 1: Wash fleece fabric. Drape it over your baby for peek-a-boo purposes a couple of times.
Step 2: With fabric folded in half, drape the fabric over front rail (the longest length of fabric should be parallel with rail). You want to leave about 10-12" of the doubled fabric hanging down in the front; enough so that the strips will be long enough to tie.
Step 3: Using your trusty scissors, snip away the extra fabric along the front bottom. The fabric will extend too far along the top of the crib, but that's OK. It will all get figured out in time, my grasshopper.
Step 4: Starting at one end, line the fabric up with the first slat opening. Cut the fabric from the bottom up to the base of the crib rail. Take care not to cut above where you will tie it. Do the same on the back side.
Step 5 and 6: Tie the front and back flaps together TIGHTLY with a sturdy double knot. Move on to the next slat opening and repeat step number 4.
Step 7: Keep going until you reach the end of the rail.
Step 8: Snip away the strips of fabric in between the bows.
Step 9: Trim up the bow ends to make them look uniform and neat.
Step 10: Repeat steps 2-9 on both side rails.
Picture Courtesy of Navigating the mothership