Zip ties, Plastic mesh garden fence 4' x 25', pressure treated wood stakes. ($15 total!)
Then I cut the fence in half so I had 2' x 50' of fence.
Pounded in the wood stakes with a sledge hammer (good cardio workout!), and zip tied the fence to the stakes.
Here's Paris in his new SAFE backyard!
Not bad, if I do say so myself!