So I'm building several raised garden beds, I already have an idea in mind using cinder blocks for various reasons not necessarily related. The issue is that the area I have chosen for my garden is an unsightly, weed infested sloped part of the yard. We live on a hill and this area is in the back lower half of it. It isn't severely sloped but enough to need care when walking, some parts are steep but it just needs some leveling. I want to flatten this area as much as possible though it is bordered by a fence of my neighbors and a stone wall on the opposite side that is another part of the yard (the whole area is about 20' by 8') so I can't just flatten the whole thing without issue. I can level it out for the most part but there would still be a slope. It was mentioned that maybe I could use pallets on the bottom of the raised garden beds to level it even more, then place black garden cloth over the top. Then the cinder blocks and fill it with dirt, to level it even more. Probably won't be perfectly flat but my goal is to level it as much as possible. though I have not seen anyone else do this or seen any thing online. I also think the pallets would minimize shifting of the blocks over time. Thoughts?

As it is early morning I don't have a picture of the area but I can provide if requested.