@longgone Here’s where your imaging approach might complicate things. Since the image is a mental construct, it’s a form of thought itself. Thoughts naturally lead off into other thoughts. Most beginners use the breath as the resting place, following the ins and outs, seeing how it is moment by moment without controlling it. Because that doesn’t require thought, it’s less likely to spin you out into other thoughts.
It’s not realistic to expect that thoughts won’t show up as you’re sitting there attending to the resting point. They certainly will. What you discover after a while, though, is that if you don’t turn your attention to them when they show up, then they just go away. So you do notice that a thought is buzzing around, but you don’t react to it by either wishing it away or investigating it. You can let it alone, keep your attention at the resting ponit, and the thought will just fade away.
Until you get the hang of this, you’ll find that you do investigate those thoughts as they appear, which pulls you off into thought land. This will happen over and over. No big deal. You just notice that you’re no longer at the resting point and, without a lot of fuss, just go back.
When you get the knack of not investigating thoughts, then the whole thought process gradually quiets down. The important thing is that instead of putting energy into fighting thoughts, put that energy into attending to the resting point. The more attention you invest there, the less thoughts will be a problem.
And here again, don’t concern yourself with checking to see whether your mind is “empty” or not. That’s just another form of thinking. Keep it super simple: attend to the resting point. If the attention slips away, bring it back. That’s it.
I keep using this term “resting point” because most forms of meditation do take up some particular target (like the breath) on which to keep the attention at rest. There are a few forms of meditation that have no fixed point, but those are much more challenging, and unless you’ve already cultivated the ability to keep your attention at rest on a point, it’s easy to fool yourself that you’re meditating when you’re actually just daydreaming.