I'm DIYing our invitations and they are certainly going to be a huge labor of love. I spent most of the day today heading around to different craft stores looking for paper that I liked, metallic pens, and other various assorted supplies, then headed home and started measuring, cutting, gluing, remeasuring, recutting, etc and finally came up with a finished product that I'm in love with.
I only have two invitations finished, but I have a lot more of the supplies cut out and ready to assemble once I find another method of assembling them. I made the first two using craft glue and the result was rather messy so I want to try double-stick tape instead.
I'm doing pocketfolds out of dark red posterboard (I can make 3 out of each posterboard sheet), then the invitation itself is printed on pearlized ivory paper, layered over "kraft" brownish paper that takes on a gold appearance against the pearl ivory. I printed the invitations on my inkjet printer, and the gold embellishments are printed in light grey which I then traced over with a gold metallic paint pen to give them a beautiful shimmer.
I have not done the inserts yet, but they will be in non-pearl ivory paper with red printing to match the invitation. The belly bands will be in antique gold, and I've got a fabulous carousel horse rubber stamp that I'm still figuring out where I want to work in to the picture.

Photoshop file of the invitation (edited for privacy)

Full pocketfold design with a piece of ivory paper to show the full layout.

Printed and embellished invitation. I can't believe how amazing they turned out.
Two down, 173 to go!! I plan to do them 5 or 6 at a time, since I have until August.