Wire coat hangers!
I don't have a washer or dryer, so I take all my clothes to a wash/dry/fold service. This causes my house to fill up with wire coat hangers after a while, lol. So I try repurposing them whenever I can. Many of them become bowl-pokers, others become hooks for hanging things (including drying branches), and a good portion of them are turned into my LST stakes.
All I do is just bend them into elongated "U" shapes and shove them down into the substrate. Works beautifully!