It's difficult to answer this question in the abstract because "meditation" as a descriptor is about as general as "exercise." Even at the level of philosophical schools there's secular mindfulness meditation, Christian meditation, Buddhist, Hindu, Taoist, and the like. Or at the level of technique there's visualization, mantra, vipassana, shamatha, jhana (which can be seen as part of shamatha), chakra, kundalini, ...<p>So a first turning point might be to discover <i>why you're meditating</i>: whether it's for curiosity, to lessen your suffering, to make yourself stronger, to answer your deepest questions, to help and serve others, to seek some kind of transcendence, to be a better person, or for any other number of reasons.<p>But let's suppose you're meditating to enact some kind of change in your day-to-day experience. Then a second turning point might be to realize that <i>your conditioning is running the show</i>. If you accept the idea that your starting point is one of ignorance and neuroticism, then if you practice alone, that same ignorance and neuroticism is running the show. This is why Buddhist systems emphasize the importance of <i>buddha</i> (here meaning the awakened teacher) and <i>sangha</i> (here meaning the community of aspirants).<p>Then if you continue this, a third turning point might be that <i>there is no separation between formal and informal practice</i>. This doesn't mean you stop formal practice; it means you treat all activity as part of the meditation and act with mindfulness and attention wherever you go. This is possible with a deep foundation in practice or with substantial lifestyle changes (such as avoiding distracting media), but usually it's easiest to sustain in a retreat setting.<p>But to put it in a sentence, I think the most important thing is to <i>get real</i> with your practice and build relationships with fellow meditators. Left to your own, there are too many traps that can waste a lot of time.