In order!
Security - BEST SKILL EVAH! Loose lips sink ships!
Experience - Comes with time and lots of mistakes!! You will always learn something new everyday!! If not, make it your new goal. Reading does not hurt one bit!!! Read everything!!!! BINGE READ TILL YOU PUKE!!! (with reading I was able to accomplish something furious my first time)
Setup - Good running environment! No light leaks, good lighting, able to manage temperature/humidity, good air circulation, fresh air(or CO2 supplemented) and last but not least control of odor!
NOW
Plan!! Make sure you have a backup for your backup! I am serious, cause when shit goes down it goes down fast! I personally have everything to a T planned out ahead of time.
Pay attention to all the details! Make sure you are giving your plants their TLC for the day! I am always on the watch for bugs, nute burn, nute deficiency, mold, snakes, highs and lows for humidity and temperature.
Each grow I start a new log where the last one was BURNED!!! I write my temperatures, humidity, PH swings, PPM swings, water used for the day. Res temp, what was added to the res, and what was subtracted.
I do this because it helps me diagnose anything that could go wrong.
and make sure you burn your log after harvest!! This is just a precautionary measure in case you get caught! Nothing like seeing you had 30 cycles before you where presented to a judge, huh?!