There’s only one way to photograph leaves, and that’s when they are backlit. All the veins are revealed and the resulting patterns are astounding!
The way I do it is put my camera on a tripod with a macro lens and point it straight down at our glass topped coffee table. Underneath I set up the flash so it points upwards. Usually I use a diffuser and often put tissue paper over the top to create more diffusion (a handy tip for those shooting macro with flash on a point and shoot camera) to ensure even lighting. I then set the aperture (and ISO) so it is exposed correctly. I usually use f8-f16, which are the sharpest points for most lenses and ensures everything is in focus.
Try it out and see details you’ve never seen before.