Difficulty: Moderately Easy
Step1
First you need to learn the specific rules of whatever game it is you want to become proficient in.
Step2
Begin playing with friends and in online poker rooms like on absolutepoker.com or fulltiltpoker.com. Start with play money rooms then after a while ease into low stakes cash games and tournaments. Also read as many poker magazines and books as possible to learn about all the different strategies in betting such as slow playing and value betting.
Step3
Play as much as possible. Seeing as many hands play out as possible will help you develop the talents of picking up on patterns, check raising,etc....
Step4
Once you feel confident try out live play at a casino. It will be a little nerve racking at first because now people can see you. But just remain as still as possible and do not talk during hands as not to give away any tells.
Step5
After a few months with the right dedication you should be comfortable playing in most situations.