We printed our labels out on white label/sticker paper (at local craft stores or target/walmart, $5/pack) and cut them out to place on packages or envelopes. You can also just use plain paper and tape/glue it on.
HELLO...is it me you're looking for?
You can find the front and back of this card below - after printing the front, simply flip the page over to print on the back and follow the cut/fold lines. We used white card stock (michaels, less than $1/sheet) and small brown envelopes (5.75" x 4.5") (michaels, $4 for a set of 25). A quick trick to get a crisp, clean fold is to run a credit card along the fold crease.
Get your creative on and use other neutral color paper for your card. We used brown card stock (from michaels, $4/pack) here.
Click the links below for the PDF's! We recommend opening these in Adobe Reader for compatibility.