The first suggestion I would give someone is to (probably) change their concept of what they are trying to do. Do not think of it as 'trying to leave your body'!
Where are all the things you see (this includes your 'body')? Exactly. Images are in your 'head'. You are used to seeing an image that you are (probably) conditioned to think of as your body, and for most practical purposes it works out to think of it this way, but though it corresponds to your body, the image of your body is not your body.

With that in mind, think of it as concentrating yourself away from where images are. Imagine the image area in your 'head' is a big planet and your attention is drawn to it automatically like a small rock by a kind of gravity. This is sort of your dilemma. What you can try to do to counter this is to concentrate intently on sensations while trying to pay less attention to images (think of where sensations are as being 'up' from where images are). Imagine moving but don't actually do so. You will probably more easily project the sense of where you are onto things that you identify with, so sitting across from a mirror can initially help.
It can be mentally a little jarring but since you are trying to do it it shouldn't be that disturbing. Physically it can also feel a little weird as your attention leaves planet-image and moves up and onto planet-touch (it should not be painful though- just...fuzzy). You are redistributing activity off the resting norm by doing this - I have no idea if it's even possible to stay this way long enough to throw something metabolically off but IMO it's probably better not to go too overboard with it, and certainly if you feel uncomfortable, stop.

Also, moving off of and around the visual area isn't the same as walking around (in 'normal' space) while watching the visual area change. That is, you can explore and influence your own space but not spy on the neighbors (ime, but hell who knows - life's weird and crazier shit becomes possible all the time).