The cards below are all made from re-used paper. The two purple ones below use purple patterned paper from food packaging (I can't remember,but I think a chocolate box). The pink shiny card is from cosmetics gift box packaging.
The green paper used on this card is from an Islamic finance brochure, each page was in a different colour so I have a few of these to play around with.
The background for the card below was from a college prospectus. Again the pages were in different colours, so I saved a few. You might be able to spot the other cards I made with this paper here (the last two in the post).
The pretty, glossy paper below was from a Swarovski catalogue.
Other sources I have used include magazines, wall-paper peices, postcards, old note-book covers, chocolate box packaging, gift packaging, wrapping paper, tissue paper and gift bags you can't use anymore. You can also try old maps, damaged/unusable childrens books sometimes have wonderful art in them, sheet music and old comics - the list is endless if you are creative. One of my favourite sources is wedding invites, which often use beautiful paper and decorations. Asian/Indian type invites in particular tend to be full of my old favourites: paisley's and jewels.
Someone asked me where I get my Eid Mubarak and Happy Eid peel-offs/stickers. These are specialist items and fairly cheap. I usually buy them on ebay from this supplier, but she has none at the moment, they are also available here and here.
If you would like to give card-making a go but feel a little intimidated, then you might want to have a look here and scroll down and see how terrible my oldest cards were (although if you really want to be intimidated, you can check out these two sisters' beautiful, professional-looking work here and here). As you experiment and play with the materials, you find your own unique and insh'Allah beautiful style.
Insh'Allah I hope to post about frugal embellishments for cards and easy techniques soon and write something about the simple jewellery I make in the near future. I would really, really welcome your ideas in this regard too, whether via the comments or e-mail.