Some of you asked about the close up lenses I talked about using - here they are above. A search on ebay for close up lenses in the photography section will find them - you just need to choose the ones that fit your camera. They were on offer from £13 to £18 when I looked (roughly double that for dollars). That's for a set of 4 at different magnifications - and you can stack them to increase the magnification.
They have a very shallow depth of field (the part of the image that's in focus) - but I love that for close ups, throwing the background into an out of focus blur of colour shows up the detail of your focal point well.
They can't compete with the proper macro lenses that you can buy for SLR's - but they can be great fun, allowing you to really close in on small areas.
I used them here http://vivienb.blogspot.com/2008/07/flowers-and-more-flowers.html and here http://vivienb.blogspot.com/search/label/macro
If your camera has screw threads for UV filters etc then you can use these.
Another useful photographic trick is to use paper tissues to soften the flash - I hate the harshness of flash and in close ups it can bleach colour like this:
forgetting to put the camera to the macro setting didn't help matters!
With tissue over the flash the result is very different:
the colours are vivid and true.
How many layers you need is a matter for experiment.
Incidentally this is the cover of Casey's book in the FPP sketchbook exchange, with a little addition from Glen in the form of the dinosaurs she's made from the loose watercolour shapes on the back cover :>)