Here are a couple I have built, a couple hints:
use smaller diameter lag screws, easier to screw in.
square off hex end off lag bolt with grinder so fits perfect in metal stock. (will not turn out on you)
use thread lock or hit with punch so bolts dont back off or come loose.
I look at thrift stores or ask many people if they are throwing out tripods, to keep for you and I recycle the heads for these.
this one is very basic, but works good, just a screw and washer, you just tilt by turning on the tree.
I have also welded a plate on one end to use as a strap on type, I also made loops for the ratchet straps to go through.
gorilla pods work great for bushes, trees with small limbs and as a small tripod.