Recently I've been contemplating making my own dividers out of pretty paper, but the cost of attractive stock of decent weight has put me off somewhat.
As well as shopping around, there is another route I could explore in order to find materials I like; paper stockists. Or more precisely, their free paper samples!
With a simple Google search you'll find that almost every reputable online paper suplier offers a small selection of free samples for anyone to order. You can even get wall paper swatches this way; not enough to do your wall, but enough to make a devider or two. Though you may have to fudge a company name for a form or two.
Another random thought: Dulux swatches as colourful, yet stylish, rulers/page deviders. You can have them in almost literally any colour.
Can you tell I'm feeling a bit creative tonight?