I feel like I’m repeating myself saying this, I did not use Photoshop or any other post processing tool. I made this shot hanging a leaf from a stick. Place a yellow paper as background. I place the set up close to a window during a sunny day. I cover the window so the background paper had all the light and the leaf was in the dark. Then, using a torch (flashlight) I illuminated the leaf from down and behind. This highlighted the leaf details like veins in a heart.
I shoot in RAW, using Canon styles to adjust contrast, saturation, sharpness and WB in the camera. Minor cropping done in Canon DPP software.