Anything can become structure if it will last under water. I use a lot of cedar when available for habitat that will be fished through. For sanctuary for forage You can literally use anything, just think of dense cover for small fish to hide in. If your lake has none you need to plan on adding enough in different areas to cover 10% of the surface acreage. Place it in 2-4 ft water. I use stainless steel or heavy duty UV protected zip ties to secure weights; the galvanized stuff rusts through.

-HH