Plant growth with orgonite isn’t an exact science, so while I can give guidance, there is not really a wrong way of doing it.
With regards to burying the pieces in the context of plant growth, I’d advise burying any pieces that may get picked up or moved if left on the surface. Having about an inch of soil above the buried piece is OK.
If there is no chance of disturbance, I like to lay pieces on the surface, applying pressure/turning them to make a good contact. Semi-burying them, or burying them so the top is flush with the soil is fine too.
For special plants, or plants that struggle, or plants you want to grow especially strongly, I use the gardenite pieces. For general use, the field grade pieces are fine.
For pots in general, a single piece is OK. For garden beds, pieces at the corners of the bed, plus in the centre should suffice.
For indoor plants, or conservatories, having gold tipped cones or standard HHG cones on window-sills or otherwise close-by, in addition to the pieces in or around pots seems to work well too.