Don't ya hate practical women... Think this means you are getting a 5 dollar gift to...
Box is a lovely idea... Can you do any kind of carving at all? carve her something to put in it... even as simple as a heart...
You can be more creative than that... Use the skills you have. You are a master story teller. Go and get one of those Journal books, book stores sell 'em, stationary stores sell 'em, even dollar stores sell 'em. Tell her some stories of your life together, events that you've shared... The good, the bad, the hysterically funny...