I had no idea how to get my hands on Adobe Illustrator, and everything I learned about PhotoShop is a vague and distant memory. I'm not too confident in my designing skills anyway, but I do know my way around Microsoft Word.
I pretty much copied a graphic I found from a save-the-date that I liked onto a Word document. Then I used almost the same wording on that save-the-date, then found similar fonts on my work computer!
I didn't know how to put four on one page like a postcard, so I just made it a full 8.5" x 11" size to be scaled at the copier's
I saved it as a PDF, put it on a flash drive and made my way to Kinko's. There, they got me my cardstock, scaled it down to fit four on a page, and made a buncha color copies! The colors turned out perfectly, and it looks like a bona fide save-the-date!
We saved a whole lot of money doing it ourselves, and now, making our own invitations and RSVP cards doesn't seem so hard!