I have recently been re-reading Bhante Gunuratana's Mindfulness in Plain English, a classic nuts-and-bolts guide to meditation that has just been released in a new 20th Anniversary edition. Although written in the context of the Vipassana tradition, and therefore focused on breath and 'insight' meditation, much of the book covers concrete suggestions for dealing with distractions of all types, and is therefore relevant to all kinds of meditation, and for both new and experienced meditators.
I particularly appreciated the distinction between 'thinking' and 'sinking' mind that Bhante Gunuratana outlines, and think these are two states of mind any meditator can relate to. Thinking mind is busy mind - when our thoughts bounce from thought to thought in a seemingly endless train of mental activity. It is very common for first-time meditators to be amazed at how busy their mind is, and to feel certain that meditation itself caused the busyness. In fact, most of our minds are always this busy, and it is only when we sit down to meditate that we begin to realize this.
Sinking mind is the opposite of thinking mind, when we fall into a kind of stupor. This might manifest as drowsiness, but often doesn't actually become physical fatigue. Gunuratana describes it like this:
"...sinking denotes any dimming of awareness. At its best, it is sort of a mental vacuum in which there is no thought, no observation of the breath, no awareness of anything. It is a gap, a formless mental gray area rather like a dreamless sleep."
Many people mistake sinking mind for relaxation, or for detachment, thinking that meditation should be a kind of emotionless, sensory-deprived state. In fact, it is a clear, alert, mindful, yet still, state. Neither thinking nor sinking mind is the goal. In Buddhist teachings, these two states are sometimes compared to a guitar string that is too tight (thinking mind) or too loose (sinking mind.) When the string is too tight, it may break, and when it is too loose, it will not play the right note. The guitar string needs to be just right for it to play a clear, clean note. Likewise, meditation is a clear, alert and yet still and focused state.
Meditating is a process of adjusting our 'mental' string, and most of us swing back and forth between thinking and sinking mind during each meditation, although we may be more prone to one than another. Our tools for tuning our strings are mindfulness and concentration.
Centering our mind through concentration and focus are the key to working with thinking mind. We use one-pointed concentration, pulling our mind back over and over from distractions, to quiet our mental activity. Whatever is our intended object of meditation, whether it be our breath, a chakra, a visualization, a mantra, or awareness itself, we pull our mind back over and over to this focal point, attempting to do so with non-judgment. Although it is sometimes useful to contemplate the nature of our distractions - the major themes, and how long each lasts for example - after doing this briefly, we pull our mind back to our focal point.
For sinking mind, mindfulness, or inquiry, is our tool. We can attempt to examine the nature of the sinking mind itself, looking at its qualities as a sensation, and comparing this with alertness. We can also contemplate how it impacts our body, or emotions. Doing this helps us to pull back from the 'dimness' of this state, into an alert inquisitive state. From here, we can return to our point of focus - again whether this is our breath or something else. If sinking mind is a recurrent problem, it's sometimes helpful to do more active meditations for a time - adding counting to a breath meditation for example, rotating through the chakras in a chakra meditation, or focusing on our senses mindfully - what we hear, smell, etc. - in order to keep ourselves in an alert, inquisitive state.
Navigating between these two states of thinking and sinking mind is something all meditators can relate to. With time, the length of time it takes to recognize these states gradually grows shorter, and the distractions themselves may change - we may get captivated by bliss for example, instead of thoughts about dinner - but we all work with this balance, with tuning our 'string'. When we find the balance, we connect with the source of awareness itself, which is what fuels both mindfulness and concentration, and with this discovery, our awakening unfolds.