Do you change your own oil in your car?
Always, as well as most of the other work on the cars.
Make your own peanut butter?
No but I haven't eaten peanut butter in close to 20 years, I do make my own jams though.
Bake your own bread?
Yes and I love the smell that lingers for about a day after doing so.
Build your own furniture?
Yes because I can't find good furniture for prices that aren't extortion level priced. That and you try finding a solid walnut desk.
While I understand the need to make things other people's problems there is a real sense of accomplishment when you do something your self. Once you get good at doing things you can generally do a better job than the quick and dirty you paid someone. When I change oil I actually spend the time while the oil is draining to check things that should be checked regularly, like belts, hoses, suspension, wheel bearings, lights, etc. I also will take care of things like knocking some of the dust and dirt out of the air filter, and changing the power steering fluid that is in the reservoir, charging the battery all the way, greasing the wheel bearings. Now add in that I can do a full synthetic fluid change for about $50 on a vehicle that has a 7 quart oil capacity and takes a rather expensive canister filter. The 45 minutes I spend changing oil I come out ahead since I would spend about 45 minutes to go get it changed and get back from the rapid oil change place and they do a shitty job which costs more and likely they would cross thread the drain plug.
It's amazing what a long-handled flat-bladed screwdriver will do to your average pin/wafer tumbler lock...
I am always shocked at how many people don't know that trick. I did that to an old fire chest I had that in all the moves I had lost the key and the fire chest was only $30 so it was the quick and simple route. Also if you damage the pins and tumbler enough just about anything will work as a key as those things wear out. The ignition on my old Bronco II was so worn I could use a small pocket knife blade in the key slot to start it. For security forget padlocks since the easy way around them has and always will be an angle grinder. Working at a U-Haul with a storage facility we were always dealing with units for non payment and eventually would auction off the contents. The day of the auction you go out with the angle grinder cut the lock, let the bidders have a peak shut the door, and sell it. A nice silicon carbide or diamond coated cutting wheel goes through those locks like a hot knife through butter, even these recommended locks.
With your bare hands?!?