The rock ledges I purchased from
Universal Rocks as sets of their DIY ledge kits. They're attached with silicone, so that will work with pretty much any type of enclosure. Universal Rocks was also very nice; one of the shelves arrived with a warped back that made it impossible to install without sanding it down, and they sent me a new shelf free of charge.
The branches are ghost wood, which I believe I sourced from Pangea Reptiles or maybe the Serpentarium Inc., whichever was cheapest at the time after shipping. The method I used would only work with wood or maybe PVC if you're willing to drill holes, not glass. I purchased some metal thread and cut it down to 4 inch sections, then used a wood drill bit slightly larger than the size of the thread to drill holes about two inches deep in the base of the branches. Once that was done, I glued the thread into the holes with two-part epoxy (JB Weld works fine) and let it set for a few days. Once done, I drilled holes in the walls of the enclosure itself and then put some washers on either side of those holes, attached the branches through those holes, and then used a nut to screw it into place. My roommate had to hold the branches at the angle I wanted them so I could get them tight enough, but that was the only part that required another person.
If I were to install the branches in glass, I'd probably look to SerpaDesign on Youtube for tips and advice, but since I have a wooden enclosure I get a bit more leeway on how to install additions.
I personally find magnets for something as heavy as a ball python not powerful enough -- even if it isn't a matter of weight, she's VERY strong and could yank something out if given enough time and determination. I'd much rather go for something permanent to reduce the risk of her pulling something off and hurting herself.