I have always wanted one of those "hang from the ceiling" type pot racks, but have never lived anywhere where I could have one. But I figured out a workaround. This is actually the third such pot rack I have constructed.
All of them have the same basic principle. Pegboard screwed onto a frame of 1 x 2's...that's pretty much it. I don't have step by step pictures of the process, but it is fairly simple. I will say this, you might want to use some glue or construction adhesive if you are going to be hanging heavy pots from this rack. I think you could probably use it with cast iron pots, just not too many.
Also, do NOT use 1/8 inch thick peg board, get the 1/4 inch, especially if you have a lot of heavy pots.
The other thing about this pot rack is where to put it. This is intended to be a sort of "vertical surface" pot rack, i.e., either hung from a wall or some other vertical face. The first one I made I did by having two pieces of peg board hanging on either side of a refrigerator, with a piece of 1/4 inch plywood going across the top of the fridge. The second was rather large and was hung underneath a shelf in the kitchen. The one shown in the pictures is hanging off the door of a closet in the kitchen of the small two bedroom apartment I live in. If you don't have a lot of space, or if you live somewhere that you can't make "heavy modifications" to your living space (like an apartment), you will likely need to figure out some "guerilla" methods to hang your pot rack.