In the event that you do become lucid Pelirrojo you can do a few techniques that seem to prolong lucid dreams.
Remaining calm is one big thing.
To stare at your hands or the ground has proven to work for many people. Something stable in the dream. It can be many things. It bring your attention back to the dream.
Our conscious always wants to override our subconscious. Many times by thinking in a left hemisphere way can result in it taking over which the end result is waking up.