As has already been suggested try and choose a substrate/background that fits the animal your shooting it can make all the difference.
For example a burrowing gecko that lives in soft substrate will look out of place amongst rocks and arboreal animals look nicer in trees. etc
I see many people have posted shots of carpets on the front lawn the pics are technically good in regards to lighting, depth of field, exposure etc but don't don't appeal to me because they're on lawn.
Even in the backyard a little extra effort like collecting a branch or some substrate can make all the difference.
Here's an example of improvising a background the shots aren't the best and the substrate is still wrong but it looks better than plain old lawn.