nothing really can enable them except for yourself. it sounds so easy but it takes people years just to realize they're in a dream and not wake up because they get excited. some will say that marijuana helps a lot, there are some other drugs too that help it

if you've ever taken an intro psychology course then you know that humans sleep in cycles, the deepest cycle being the REM (rapid eye movement) cycle. aiming your lucid dream towards this cycle produces the best results, to do it sleep for exactly five hours, wake up for exactly one hour concentrating your thoughts on lucid dreaming, then go back to sleep. it's called the Wake-back-to-Bed method.

if you're interested in lucid dreaming you should really check out www.dreamviews.com