“Before meditating, we must first set an intention. Normally, we select a mandala that appeals to us. It is good to know what the meaning of mandala you’ve chosen – or set your own meanings/intention before focusing on it.
For example, focusing Native American labyrinth mandala, we know this meaning of mandala relates to beginnings, our enternal nature, and how this is relative to our life journey. So, before meditating on the mandala we set the intention to more clearly understand our life journey, or be shown guidance in a particular area we are having trouble on the path.
Once we have set our intention, we begin to focus on the mandala. Let your eyes take in the beauty of the designs, allowing your mind to wander as it will. If your mind begins to chatter (i.e., I should do laundry, have to get milk, need to finish that report for work), simply bring your attention back to the beauty of the mandala. Get inside the mandala, simply fall into it, swim in it, let it absorb all of your attention. As you fall into the mandala, you will begin to feel lighter, and intuitive thoughts may arise. Relax and float with the thoughts and feeling that come to you. If you begin to feel lost, uncomfortable or if you get the “chatter” again, simply focus your attention back on the mandala.
Each observer has different experiences. However, the overall consensus is that meditating with the mandala leaves the observer relaxed, and he/she comes away with a resolution or clarity concerning the intention that was set before the meditation.” – source: http://www.whats-your-sign.com/meaning-of-mandala.html