Hanging/suspended shelving

Need a shelf in our kitchen, only available wall is stud/plasterboard, with sparse studs & slightly shitty board, however, there are some decent beams above, so was thinking that would be an option, but can’t find much suitable.

I can make a timber shelf easily enough, just need wires/brackets/fixings, any ideas/past experiences to share?

Have used threaded rod + bolts/washers to suspend a computer shelf below a desk, if you can get it long enough and don’t mind the slightly engineering look, it works well, and infinitely adjustable!

Chunky rope through holes drilled in reclaimed planks with figure of 8 knots under the planks