If you have to pick up long lengths of wood from the lumberyard, throw a spring clamp in the back of your vehicle. Use the clamp to attach the warning flag to the end of the protruding lumber. The clamp’s easy to slip on and off, and you won’t have to fuss around with staples, nails or string. — Steve Parker. Plus: Learn more about how to transport large items in your truck.
This plan is probably the easiest plan ever added in the list. The one who is working on this project, don’t need any professional skills but just knowing some basics of woodworking will be enough for this DIY. You will get step by step detailed process of this tutorial in the source linked tutorial. This tutorial will surely help you to build this plan quickly.