With a Craftool A104 or similar tool, background the inside of the mouth down to the lower lip that extends beyond the front of the fish. Make sure that the borders of your back grounding impressions are crisp and depressed.
With a Craftool F916, create the grass branches on the three cut lines in front of the fish. Please practice on a piece of scrap leather to understand how this tool will make the impressions. Imprint one tool stamp on the top of the each branch.
Here are a couple of tricks. Tilt the tool forward with the F916 tool when creating the impressions. You will avoid cutting off the impressions with the base of the tool. Also, place a couple of impressions around the bottom of the water around the rocks. For a 3D look, create some faint impressions for distance plants and keep impressions for up close plant life.