I certainly didn't have guardsmen conversions in mind when I purchased a box of Dryads from Warhammer Fantasy. Instead, I wanted to do two things: grow my bits box with a variety of interesting odds and ends and create enough "trees" to give myself an authentic-looking mini-woodland modular scenery base.
To that end, here's the first of my woodland dryads, mounted on a regular warhammer 40,000 circular base. The painting of the dryad has been kept deliberately low-key and simple: various washed of browns and blacks over a grey base coat with very few highlights. The eye of the dryad has been picked out in codex grey mixed with skull white to make it stand out a little.
The final touch was to glue in place a big wad of tree flock on the dryad's outstretched hands; giving the impression of passiveness, rather than a dryad that is ready for warfare. Having said that, I think the model could do well for a bio-themed Death Guard generic lesser daemon as well(!)