There are a few things to consider when painting a green snail on a green leaf. The first is the color of the snail. You want to make sure the snail is a different color than the leaf, so it stands out. You also want to consider the texture of the snail and the leaf. The leaf will be smooth, while the snail will be slimy. This can be a difficult contrast to paint, but it will be worth it in the end.
Once you have the colors and textures down, you need to decide on the composition of the painting. You want the snail to be the focal point, so it should be in the center or slightly off to one side. The leaf should be positioned so that it looks like the snail is crawling on it. This can be accomplished by painting the leaf in a curved shape.
Finally, you need to add the finishing touches. This includes the highlights and shadows. The shadows will be darker on the side of the snail closest to the leaf. The highlights will be on the side of the snail furthest from the leaf. This will give the painting dimension and make it look more realistic.
With these tips in mind, you should be able to paint a green snail on a green leaf with ease.