Great advice from all previous posts, but also consider doing a "tool layout plan" to have an idea as to how large your "simple wooden box" should be. Gather all your tools, group them together as you'd want them in your tool box (use a flat surface or the floor), measure top to bottom, left to right, and the height of the entire area they will take to fit neatly in your tool box. Maybe take a few pics to keep for reference. This will give you a starting point as to how much material (wood) will be needed to build the tool box. Some larger tools could be put into one tool drawer, and smaller items in another, but make the drawers stackable. Be safe.