You can never have too many wall hooks in your apartment, and mine are always full. But given that your average piece of bent metal will run you $5 a pop at a Manhattan hardware store, I've limited my urge to line my walls completely.
If only I lived out in the sticks, I could use sticks.
Etsy seller Gabriel Rutledge makes hers out of green maple twigs mounted to a distressed wooden board.
John Robohm's Live Wire Farm is a Vermont-based outfit that manufactures goods from local hardwoods, and judging by all of the SOLD stamps on their website, does a brisk business in hooks.
Homemaker Graca Paz cobbled up a set from local materials and documented it on her blog dedicated to living in the Portugese countryside.
Another Etsy seller, Jack Pollner, takes advantage of New Hampshire's snowfalls to harvest his raw materials. After heavy snow fills the area around his house with downed branches, Pollner collects them, cuts them to size and assembles them into hook racks.
So, yet another reason for me to envy those who live in the country. The only urban equivalent I can think of that could be readily harvested are the cheap, broken umbrellas filling every curbside garbage can after a heavy rainstorm.