In Photoshop create a new file that is at least 400x400 pixels, it doesn't matter how much bigger as long as it is square. Create any texture you like and save it as a jpeg file. In Bryce select a simple white texture from the simple and fast texture menu. Click on the upper left dot in the diffusion row. A texture will appear on the right, click on the little "P" button and then the button directly above it that says "texture source editor". This will take you to the picture import lab. Click on any gray box, or click on "load", select the texture you created and it will appear in the left and right box. Click on "Copy" in the left box and "paste" in the center box to create the bump map. Close this window and change the "Texture mapping mode" to conform to the shape or terrain you are texturing. Adjust your diffusion, ambience, specularity, etc... to suit your tastes. When you are ready to save your new texture click on the material library link next to the nano preview window and at the lower left of that menu click on the triangle next to "Installed" and select "User". Click on "Add" and name your texture and you're done. For complex textures you can add up to 4 channels for bump, ambience, reflection, etc.... That's the quick and easy way.