I spent yesterday afternoon making cards and envelopes. For the cards, I used double-sided pages that I'd saved from an old Lotta Jansdotter address book. I folded each page in half and inserted a slightly smaller folio of translucent paper for writing on. To secure the two folios I tied embroidery floss around the fold. I made 20 of these; they are about 3 1/2 x 5 inches.
For envelopes, I used odd paper I've been saving and some old military field maps I got years ago when the museum I worked at was throwing them away. I used my circle cutter to cut an 8" circle and then folded it around a card. I cut the triangles out from between the flaps and then glued the bottom flap to the side flaps.
Below left are two finished envelopes. The paper with the birds on it was what my printer produced when I ran some test or other on it - I thought it was so cute so I saved it. On the right are some other envelopes I made from an old calender. These envelopes are squares with four half-circle flaps, and I made them the right size to hold a CD.