I use chicken wire over the lower portion of the hoop house and deer netting over the upper portion just to keep the deer out. They are evil varmints here. I also purchased a large piece of 30% shade cloth from Farmtek for the top portion.
BTW, my hoophouse is modified. The single hoop became too narrow too fast, so I added a 10ft wide section down the center for additional space. Y'know, it STILL isn't big enough! Here's a pic to show what I'm trying to describe:
The chicken wire and deer netting is held in place by zip ties. It easy and economical. The top cover is held by shade cloth tabs (find at Lowe's or Home Depot) and tied into place with string so it can be moved out of the way when needed.
The tomato plants Mrs S is standing by have grown through the top covering, so it's currently tied back.
The bases are just rebar that was hammered into the ground and the open ends of the steel poles were placed over them. If you need to tie it down, the steel toprail can easily be drilled through to provide tie-down anchor points.