I was interested in your comment about building up enough concentration so you can switch to vipassana - could you say a bit more about that, and about how you approach vipassana? I assume you view it as a separate method?
I do view vipassana and samatha as separate meditation practices with different goals and results. The monks at the monastery I attend place great emphasis on vipassana, even for beginners as it is seen as the most effective and direct technique for realization. They instruct us to start with our breath by noting, "breathing, breathing, breathing" or "inhaling, inhaling, inhaling" and move into observing sense objects by simply noting, "hearing, hearing, hearing" when a sound arises and when you become aware of your hands resting on your lap you will note, "touching, touching, touching". You can note objects in several different ways, actually. We simply follow the different categories the Buddha presents in the Satipatthana Sutta. For instance, you can choose to note in terms of the five aggregates, the six sense-bases, the four elements, or some other option that the Buddha presents. (I find noting in terms of the sense-bases is most effective for myself. Other people find greater success noting the aggregates.) You are always placing awareness on what is arising and noting when it dissipates. In vipassana we want to observe the three marks of suffering, impermanence and not-self in our body and mind. I have been instructed that only insight meditation can lead to the four fruits of stream-enterer, once-returner, non-returner, and arahant. Samatha can lead to rebirth in the Fine-Material and Formless Realms, this means you are still in samsara but it does serve as a good "backup" destination if you are unable to attain at least stream-entry in this lifetime. The danger of samatha is that you can become attached to the more intensely pleasant feelings and lofty states of consciouness that will arise in this practice.
The subject of which to do first, vipassana or samatha, is another area where you will find disagreement even among contemporary Theravada teachers. Some, such as Pa-Auk Sayadaw, teach that samatha should be mastered up to the fourth jhana before you even attempt vipassana! Though he does allow for an alternate route where you move more quickly into vipassana practice.
I think the two techniques are best developed in tandem. My tradition, though it emphasizes vipassana, does not discard samatha by any means. Again, we are taught to begin with our breath as it is easy to work with and lends itself to both types of meditation practice. Building up concentration in a meditation object allows your mind to relax and be temporarily free of the hindrances which will allow it to be more effective in being aware of the present moment. Of course, the hindrances can be an object for vipassana practice too as the Buddha instructs in the Satipatthana Sutta.
