There seems to be quite a lot of heat and light over not a lot of disagreement!
For my inflammable contribution, I find that a consideration of the physics involved is very useful at times. For example, lifting your own arm upwards (when on earth!) only works if there is an equal and opposite force acting on the earth through your body. Typically your feet, but it could be your bum and the chair you are sitting on. A lot of people have very little awareness of the forces being expressed in their body to do such a simple action. I personally find it very useful to dial up my attention to become more aware of these things in my own body.
The more I increase such awareness of my own body, the more easily I am aware of my partner's body during aikido techniques and how it is affecting my own posture, when their balance is compromised etc.
Equally, I find that this acute awareness of balance and force is hugely beneficial for weapons work. Most people tend to "muscle" bokken or other weapons around in space without being able to relax and feel the balance.
Having said all this, I find that various forms of imagery and mental constructs are also really effective at changing the state of my body. An image such as extending my focus out several meters from my body and imagining a sword extending to that point can make a technique work that was previously being blocked. It also works for my students regularly.
The more I teach the more I realise how other people are really strange and why can't they understand the simplest things that I have so clearly explained and demonstrated that only took me a few years or decades to understand. I regularly realise how much I must have dissappointed my own teachers on a regular basis