I had an old door sitting in the shop for what seemed like forever. I don't remember where it came from, or when I got it but odds are pretty good that I saw it laying near a dumpster in an alley and I brought it to the shop. There isn't a huge amount of salvageable lumber in those old doors, but they come in handy from time to time.
For example, the rails and stiles are almost always douglas fir, which is a pretty decent softwood. And, it can be pricey to buy it new.
The panels are almost always solid wood, and those come in handy when I need to build a quick box in the shop to hold scraps, tools, hardware, etc.
The doors almost always have multiple layers of paint, and that paint is almost never the same color from one door to the next. I use that painted door "skin" for veneering random stuff from headboards to cutouts of various shapes and sizes.
Granted, it takes a little bit of work to get to the usable material in the old doors that have been thrown out, and I don't make a habit of bringing too many doors into the shop, but having one or two on hand can make for a decent rainy day project. And, if I really feel like looking around, I can always find one being thrown out...which means they don't cost any money to buy.
Similarly, on more than one occasion I've had a client tell me they have an old door - usually from a house with sentimental value that got demolished for one reason or another - but didn't know what to do with it. There are a lot of ways to reuse old doors, either leaving them kind of as-is, or carving them up, salvaging the lumber and building something with what's underneath the surface.
Anyhow...I had this old door laying around the shop and I was tired of bumping into it. There's usually enough lumber in an old door to make the legs and apron for a small table, and I have plenty of other reclaimed lumber in the shop that would make a suitable table top, so...I figured that's what I'd build: a small entry/hall/sofa table, using the wood from the reclaimed door for the frame and some reclaimed 2x4s for the top.
It wasn't an exercise in check-out-my-technical-woodworking-chops so much as it was a project in taking a pile of things literally headed to the landfill and building something halfway decent. That said, it was the first time I'd gone with the reclaimed douglas fir frame + reclaimed framing lumber top, and I wasn't thrilled with the resulting look. But it was still a pretty fun project, and definitely a little different from building big, beefy tables and dealing with larger lumber like I've been doing lately, which made it a nice change of pace.
This is one of those builds I had the time to film, so I cobbled about 70 individual clips together and condensed them down to 15 minutes, which is never easy. I could have probably made 3 or 4 videos from this build and gone into more detail about the mortise and tenon joints, or the router, or the jig I threw together pretty quickly to cut the tapered table legs...but I get a headache just thinking about editing all that video, so 1 lengthy, fast-paced video it is.