Magic, Bullfighting, Front-loaders, and Aikido
I find I use a lot of images to help me visualize the form and energy of techniques.
I think of some techniques as being like bullfighting (which I despise, but that's another conversation). You give Uke the impression they are targeting you, until the very last moment, and then you aren't there. For example, fading straight into a strike and then rotating off the line of attack.
Other aspects of techniques are more like slight-of-hand magic tricks. You draw Uke's attention with an atemi to the face (for instance), while quietly taking their balance before they've really noticed what you are up to. Like handing someone their watch after chatting with them for minute. I think it was Ledyard Sensei (?) who mentioned (at a seminar) a dojo that brought in a professional, performing pickpocket to demonstrate that kind of distraction in action.
Another image that's helped me a lot is to think of my own movement/posture as being kind of like a front-loader on a tractor. I happen to have a tractor with a loader, so I'm pretty familiar with this. My tractor doesn't use its "arms" to move things, it uses its "body", through the extension of the arms. The "arms" always stay in front of center - they don't swing around, they just go up and down in front of center. If you want to move something, you don't shove with just the front-loader attachment, you connect to it with the loader, and move through that connection with the entire machine. I've mentioned this idea to a few training partners who were letting their extension collapse, and then trying to push with their hands, or letting things get off to the side, and it seemed to help them use their whole body through their extended arms, and keep everything in front of them.
Here's one that only works on people who've mucked out horse stalls: Jo parries are very much like the motion used in flinging manure into That Pile Over There. Most people have no idea what that's like, but I had one beginner totally get it on the first try after I suggested that image. Something related, that does work for many people is to suggest holding the jo like you'd hold a shovel when moving gravel - a good grip with your hands far apart, not both grasping near one end, which is where a lot of people seem to start out.
And finally, one I was just playing with in my own mind last night - how aircraft wings lift planes. It's not by air pushing up from underneath, it's from the lower pressure on top drawing the plane into that space. I like the idea of creating a low-pressure area for Uke to get sucked into. Dunno if I could communicate that adequately to most people, but a pilot would get it right away.
Anywho... I'd love to hear of any similar ways of visualizing or explaining aspects of Aikido. Anything that works for you, or you've used to explain or demonstrate concepts to students, or help them get the right feel for something.