We keep the cats' dishes and litter boxes in the basement. When Quinn came along, we needed to figure out a way to prop the door open yet prevent unauthorized excursions down the basement steps. My wife put in a 4" hook and eye, which did the trick - but it certainly wasn't aesthetically appealing. But we were hesitant to put in a cat door: I didn't want to cut up the basement door, which was original to the house. And I'm not what you'd call handy. But the breezes coming up from our unheated basement finally pushed us over the edge.
A couple of days ago, I was home from work, the boy was at day care, the wife was working, and I ran out of excuses. I borrowed a jigsaw, set up a couple of sawhorses in the basement and took the door down. (I should point out that my wife had asked me if I planned to take the door off the hinges before attempting to cut the opening for the cat door. This may sound funny, insulting or ludicrous, but those are all reasonable adjectives for describing my carpentry skills.)
It's a big cat door - 'small dogs or large cats,' the box says. We have one particularly large cat, Enzo. In his defense, he is actually big-boned. He's the most sedentary of our cats, and up until recently he outweighed our son. If you saw him on the street, you'd probably think he was a raccoon. (Enzo, not our boy. Well, probably not the boy.)
Anyway, the door came with a template. Drill holes at the corners, just a jigsaw to cut between the corners, then insert the door. It was complicated in that the door has a panel, and so I had to cut into the base of the door and the panel and somehow make the cat door look reasonable. The jigsaw was literally a pain to use: cutting through the door was slow and difficult, and it tended to veer to the left. It had a laser light which gave me continuous feedback on how far I was straying. By the time I was done, my hands were sore, and a somewhat trapezoidal cutout had fallen to the basement floor.
There's a small bit of detail on the edge of the panels, so I was off to the home store to try and find moulding that would match. It occurred to me that I could take the cutout from the door with me, which would make it easier for me to find a matching piece of moulding. Given the wandering and jagged edges of the cutout, it would also make it easier for me to look like a total boob.
I decided to use some quarter-round to frame the cat door and hide the part of the cat door that was over the panel. As a plus, I had some quarter-round in the basement; you see, I meant to do some of the finishing work from when we had our house remodeled. More than four years ago. On the plus side, I have over a hundred feet
of quarter-round waiting patiently in the basement, and even I couldn't
burn up that much while I was framing a 8" x 10" cat door... right?
I would cut a second 45-degree cut to partially hide the transition from the panel to the raised part of the door. I got out my compound mitre saw, since I would need to make 45-degree cuts to fit the pieces together. Have you ever taken one of those aptitude tests that shows a three-dimensional figure and asks what it would look like if unfolded and laid out flat? Yeah, I wasn't really good with those. So I'd cut the 45-degree angle, then realize I had cut in the wrong direction. My process is exacting: Measure twice, line up on the mitre saw, measure again, line up, cut, swear, find another piece of quarter-round.
Eventually, I figured out how to cut two pieces of quarter-round at once, which would allow me to cut two pieces the same size, but also make it easier to keep track of where the cuts should be. I was pretty proud of myself. And then, on the last pull of the mitre saw, a small chunk of wood flew from the blade and hit my hand. It wasn't much - just a scrape - but it restored my faith in my lack of woodworking ability.
The end result, though, wasn't bad:

I'll need to paint eventually, but I figure that'll be a quick job, something I can do while I'm painting the rest of the woodwork. Any day now.