One of the first signs that you are meditating correctly is a sense of greater awareness. This simply means that you become more aware of your surroundings and of your own thoughts and feelings. You might notice things you've never noticed before, or you might start paying attention to things you wouldn't normally notice. Along with this separation as an observer, comes a connection with the divine.
The quiet, calm, and peaceful part of you that is always lurking in the background appears in the foreground with amazing clarity and alertness. The simple being has power like never before, because during meditation you can experience the ONLY BEING and the divinity that entails. Don't beat yourself up if you don't experience the best form of meditation every time you practice, there's a lot of substance and peace just with the practice of setting the scene. If you can't clear your mind and focus only on the object, word, or activity of your meditation, you'll succeed.
If you are able to reach that state of mind, either every time you meditate or just a few times, you are meditating correctly. In fact, the daydreamer may leave his seat looking fresher and more relaxed than when he started, while the meditator may appear exhausted. During meditation, you'll notice the space between your divine being and the things you experience in the physical realm. However, I urge you to take note of these factors, to keep them (and any other expectations of meditation) at bay and when you sit down to practice.
One of the most wonderful and profound things about meditation is when you start to realize that you are missing out in that moment. The good news is that mindfulness in and of itself trains those skills, but of course the bad news is that you must meditate properly to gain them. These are some common factors in most meditation practices that will let you know if you're doing it right. If you've noticed any kind of increase in consciousness or in your senses, you'll know that you're meditating correctly.
That's why all those moments before real meditation are just as important to help us learn how to set the stage. This is nothing to be ashamed of. I and many other well-known meditation teachers use therapy as part of a comprehensive approach to mental health. It's hard to say how long, but if you haven't had a vision it doesn't mean you're not meditating properly.
But remember that even if you find that you can't calm your mind while trying to meditate, you can still be relaxed. For best results, experiment with different types of meditation, spend a little more time each day, and most importantly, follow a routine.