Cheap Vinyl Fence
A few weekends ago, Han and I put up some vinyl fencing so we could let Mabel out into a part of the yard without having to worry about her escaping and running (which is something she does well, being a greyhound). This is the same thing we did at the house we were renting, and it worked fine, with only one real problem - it's ugly as hell. Vinyl fencing is the equivalent to that crummy furniture you buy when you're in college or starving in your 20s – it works, but your parents aren't going to let it into their house when you come home to leech off them for the summer.
So, a few days later we were off to look at cedar fencing, and we'll be getting some of that for the more visible sections of the yard.
Fencing seems like the sort of thing that you probably want to get a professional to install. I'm sure we could do it, but it'd be slow, we'd screw something up, and if we let someone else do it, then we can call them to complain when it's broken. Of course, I'm writing as someone who does a lot of things that should be left to professionals - car work, electrical work, running wires, cooking rare meat, etc, etc.