Sean McNamara has some decent starter books on it, Trebor Seven on youtube has been doing it forever. Michael Echanis did some neat stuff too. The biggest object I ever got to was a tv remote and an empty glass - both of which were somewhat on accident. I haven't practiced much in awhile but I know it must be able to scale up somehow. Energy work warmups will definitely help but somehow we tend to get in the way of ourselves doing it. Objects will also tend to repeat programming you successfully send - they will either keep moving or in the case of silverware keep bending even when you're not focusing on them.
There's probably a particular range we need to tune into to master it, similar to hemisync or working with crystals where once you've used them for awhile you're able to recreate the vibration/energy consciousness state without needing to use it. There's probably nothing stopping us from scaling up the spoonbending shit into bending rebar except for ourselves.