When I am breathing and I notice a thought, I immediately come back to the breath. Maybe I don't realize it, but I am not saying to myself, "ok, there's a thought" before coming back to the present.
Do I need to? Or am I already doing that by coming back to the breath?
This is a really key point.
Firstly, whether you say (or think or vocalise) "okay, there's a thought" is not really important. You can notice and acknowledge a thought without having to comment upon it; though I'd suggest that it is perhaps more common, and more useful, to acknowledge the thought by reflecting upon it. This allows you to see (acknowledge) the thought more clearly.
Here's a metaphor to consider.
Your thoughts (and emotions) could be considered like fires; they might be blazing bushfires, or they might be quietly smouldering embers. Either way, the action of returning to the breath, when you notice one of these fires, is akin to dousing the fire with water, or stamping it out. This can be effective, temporarily, in cooling things down.
However, if you always stamp out these fires, you are unlikely to learn much about what fuels them; so the conditions in which fires arise remain. Sooner or later, you'll start thinking again, and you'll probably relate to the thoughts in the same old ways, with little insight into how they get started, what perpetuates them and the various ways in which you might be unconsciously fanning the flames.
Acknowledging your thoughts, on the other hand, can help you to see into the various ways in which you fuel your thoughts. However, for this 'acknowledgment' to really be useful, you need to let your thinking go on for a while. You don't necessarily need to 'fan the flames', but you can just let the fire burn. It will burn itself out eventually, and then you can reflect back and see what was going on as you were thinking. How were you relating to the thoughts? Were you throwing fuel on the fire?
As you do this, you will also develop the capacity to tolerate, or even welcome your thoughts; so they will cease to be such a problem in your meditation, and in your life too. This kind of acknowledgment is much more sophisticated and nuanced than the usual recommended strategies (for example, those in which you are encouraged to label your thoughts with simple descriptors such as 'planning, planning', 'worrying worrying' etc.) When we label our thoughts too abruptly we are not really acknowledging them fully. What we are doing is more akin to dismissing them. When we say 'thinking, thinking' it's as though we tell ourselves: "Oh, I know what's going on here. Just more thinking." But we haven't really seen what kind of thinking is going on. We think we
know it, but all we've really done is to slap a judgment on it.
For a more detailed exposition on this topic see my recent article:
http://melbournemeditationcentre.com.au ... nt-moment/If you do try out what I'm suggesting above, please let me know how you go. You'll likely have more questions as you proceed down this path.