Having enough sleep seems to be key. I don't actively do any practices to engage in lucidity . Lucidity came to me, fast and heavy, before I even knew what the term or concept was. However, as I have gotten older the natural tendency to become lucid has waned and have not experienced very many lucid dreams in the recent years.
I have noticed that two things seem to be key I becoming lucid and the first is having had an abundance of sleep....more than enough and never from a state of sleep deprivation.
The second is visualization. Basically allowing the mind to wander and observe images before sleeping and keeping that pesky inner voice silenced.