A few years back I decided I wanted to get 'a bit stronger', in particular, get stronger arms. But sometimes these fads don't last long, so I wanted some zero cost, zero clutter ideas.
I started with the bath! I used it for inclined pushups, I couldn't do a pushup on the floor, so using the side of the bath allowed me to make a start, and then I wanted a pulling exercise, so I made a pull-up bar. As I did this some while ago, and it is very simple, and using bits I already had, I only have photos of the finished article.

Now as I couldn't do a proper pushup, it won't surprise you to know I couldn't do a pull-up either; so I made it so I could have the bar at three heights.

I started by doing what I called 'let downs', which I've since discovered are called 'negatives', I'd start at the top and lower myself slowly, I also discovered I wasn't doing pull-ups, but chin-ups. The difference is which way round your hands are, palms facing is a chin-up, it's mainly a bicep exercise; chin-ups are much easier.

Supplies

Some 2"x4" or similar, a weightlifting bar, although a strong broom handle would do, maybe some screws.

Step 1: Support From Above.

My garage has open rafters so I figured I could hang my bar from the joists. After scrapping several more complex ideas, I decided to utilise some spare 2"x4" I had left over from building a shed, and the handles of a defunct door handle.

As I couldn't do a chin-up there was no point in having the bar so high all I do could was hang off it, so my supports allowed the bar to be set at three different heights. The lowest height was just high enough to walk under, the top height was at fingertip height, and the middle was, well roughly in the middle, but I never actually used that position.

So having figured out how long the 2"x4"s needed to be I cut my wood, allowing a few inches below the bottom hole, (at least a couple of inches, but if there is a chance you might walk into them, make them longer, then hopefully you'll see them and not bash your head!) and about 6" at the top for the slot to attach them to the joists.

The construction is very simple, drill some holes and cut a slot in the top so that it fits around the joist; as a picture is worth a thousand words see the images above.

But just in case you can't see the image; about 2" from the top drill a hole in the 2" side all the way through. Then cut out a slot the width of the joist, so it can fit (tightly) around the joists. I had an old door handle that had a straight metal bar as the handle, so I used that - I have to justify keeping all these odd bits! But some thick doweling would work just as well; as the slot is a tight fit and the supports are thick enough, all the force on the dowl would be straight down, it won't bend, so it doesn't actually need be very thick, and if you were concerned you could also screw through the supports into the rafters.

Step 2: Mark Up the Bar Heights

Having cut the top to fit around the joist, put one up, and then mark at fingertip height, and just above head height. Take it back down and clamp both bars together, so you can see your marks, and the tops line up.

I already had a full-length weightlifting bar (I think a cast-off from my elder son) any way you could buy one secondhand or some steel tubing or even use a decent wooden pole, like a broom handle. If you use wood it's important to not have it too long, so you can hold onto it close to the supports; that way it will not bend, or break!

Drill the holes as square to the wood as possible, otherwise it becomes hard to feed the bar through.

Step 3: Final Assembly

Put both supports up, feed your bar through one pair of holes, and you're done.

As I started with the bar just above head height I didn't want too much bar sticking out the end, to reduce the likelihood of someone walking into it. I was able to use a weight clamp, but any form of clamp would do, to make sure it doesn't slip out of the support.

You can also see, as I no longer need the lower holes, I've cut the spare off the bottom of the 2"x4"s, and cut the corners off.

I've enjoyed using this whenever I've had to go out to the freezer!
I hope you enjoy yours too.