Check colour contrast by creating a greyscale image of your web page
This very simple tip will help you to check whether the colours you have chosen for you web pages have adequate contrast.
Take a screen shot of one of your web pages, and open it up in a image editing program (e.g. photoshop). Desaturate the image to remove all colour, so that you end up with a greyscale image.
Viewing the page as a set of contrasting grey areas, makes it much easier to see whether, for example, there is sufficient contrast between the background colour and text. I was reminded of this tip while reading the Techdis article Colour & Contrast Accessibility Issues: for the design of e-learning materials by EA Draffan and Peter Rainger.