I once saw a Salem video but I am unable to find it again. It showed how to position a lifted item (on your back) by creating a "h´ghost image" of the item on the ground and then move and spin this "ghost image" until you like the position and then drop it at exactly that position.
This is a nice way to lay out container in a row for example.
Under the thread "How to UI" I can not find these commands.
Maybe they just work with the Ender Client I am using. I tried it and it worked but I forget how to do it. Didn't wrote it down in my Salem notes.