For example I would put dumbbells on the ground giving my hands an extra inch or two of height above where my head sits. My logic: just to alleviate some of the weight/pressure going to my head and thus my neck since I already have terrible neck posture and it's very difficult for me to put it into a comfortable position otherwise.
I have noticed the exercise feels a bit different this way but mostly it just seems like more work on my shoulders with a slightly different balance point.