Making Dark Images Look Better
For people who do not own SLRs like myself, Photoshop can help improve image quality significantly. For underexposed shots like the one below, use shadow/highlights or levels to brighten up the image. Then increase the vibrancy to make the image look 'prettier'. Images like these are very noisy. Use the smart blur tool to minimize this noise. Careful not blur the image too much as this will reduce the detail of the image.
More About Colours
By tweaking the the colours of this plant using the selective colour option under adjustments we can give a surreal Avatar-ish effect to a normal looking plant. Also try to adjust the levels of the image...see what turns out best for you. Happy trying!
Important note: There is no right or wrong in Photoshop...as long as the final product turns out great, then you good to go!