I had three of theese "lucid moments" where i waked up instantly after realizing i was dreaming. The fourth time, i was able to stay in the dream for about 10 minutes, and the reason for that i think was that i had a very low level of lucidity, so perhaps it wasn't such a big surprise when i became lucid. I didn't think to use any of the known methods to increase my lucidity. Perhaps a good way to stay longer in lucid dreams as a newbie is to try to have low-level lucid dreams? Don't worry, you'll get past that first stage pretty fast if you keep at it.