Place the bricks or the concrete blocks apart so that one tier of your electronics fits between them.
Lay a wooden board across the first tier of electronics, so that the bricks support the board and the board does not touch your electronics.
Make sure your first board is sitting securely. Then stack bricks or blocks on top of the ends of the board, so they match the first layer of bricks.
Set another layer of electronics on top of the board.
Place another board on top of the bricks you just added to the media stand.
If you wish, add another tier to your media stand. More than three tiers is not recommended, because the structure must be stable. When finished, place your TV on top, make sure all your electronics are plugged in, and enjoy!