How do you increase your self Discipline?

Ok so I want to increase my self discipline, and also not get distracted easily. For example if I am in the common room at sixth form, I will do my work and not talk, or if in cl my teacher ain't here I want to do my work, finally the foremost one is at home, I want to start revising and doing my work at home, so here is the deal, I have lots of distractions, A) My family B) PS3 & C) Laptop/Anime, I want to stop myself from doing this stuff at inappropriate times. What do you thing the best ways of improving self discipline are?? Please no complex suggestions, like Yoga etc lol. :) Thanks