A rope bracelet - reminds me of making friendship bracelets back in the day. My right second toe used to go numb because I'd hook the end of the bracelet over it, and then knot embroidery floss for HOURS.
I love you clothes pins: Write a message with a FINE POINT sharpie so it doesn't smear. Write "I love you" on a paper. Cut it out, and hot glue it to the clothes pin end. Would be cute for a care package!
Ultimate Knots The Non Slip Loop Knot. The strongest loop knot you can tie. Used by big game anglers worldwide. Easy to tie, far stronger and more reliable than the old fashioned strangulating figure eight knot that can substantially weaken line.