Reality Checks are talked about ALOT when it comes to trying to lucid dream, alot of people do "Reality Checks" throughout the day, they make this a habit and sooner or later whilst dreaming you will complete a reality check only to realise that your dreaming!
the reality check I have been using is to TRY to push my right hand index finger through my left hand palm, and if you can do this...then your most likely dreaming
another reality check that's often used is to look at your hands, look away then look back at your hands and notice if anything is different or unusual (change is size/shape/number of fingers) also trying to read text is often very difficult in dreams and some people use this as a reality check.
Although I did a reality check once in my dream, (the finger through palm method) but still didn't recognise it was a dream! felt like such a wasted opportunity!
Also I've not researched too much into supplements but some people swear by them, may be worth having a quick look on the supplements section of the forum.
Good luck and I wish you many lucid dreams!