I just put some different links together and bagged them up in a quart-size ziploc bag. I rolled the bag down quite a bit so the links wouldn't shift so much. Next, I printed out my card and attached it to some card stock to make a fold-over card. Once your card is assembled, just fold over your bag and staple at both bottom corners.
Are these links really lucky? Who knows? But you are, since you've found a super-cute gift idea for a super-low price. And of course, we must not forget that people are going to think you are just the coolest parent ever!!!