from Jiu Jitsu Life.
1) Never back down from sparring the toughest guys in class - Each sparring session, put your ego aside and roll with the best guy you can find, also spar with heavy guys, quick guys, and guys with unlimited endurance. As a beginner, you are under no pressure to be brilliant, so use that time to open up your game and test the positions you know against guys who know what they are doing.
2) Work on a new area until you feel it is one of your strengths, then move on to another. Work on keeping your guard, for example, until it is almost impossible for any other equal belt to pass, and really difficult for someone advanced to get by. Then add your sweeps. Once you are sweeping same belts easily and higher belts on occasion, move to submissions from the guard, etc...
3) Find positions that fit your game and work them in sparring until you can rely on them against just about anyone. Against tougher guys you need a technique you can go to from every position . Against guys at your level you can work your entire game and not worry too much about forcing them into your best positions.
4) This one should be #1...Consistency - Set a schedule for yourself and do not let anything that is not really major interrupt it. Some guys get good really quick, but the best guys have all put in countless hours to get there. You will never see your game go up if you are missing classes or weeks of training.
5) Study everyone else's game - When you are not sparring, study your teammates games and try to pick up their effective moves. Go over it in your head as they spar. Think about when you would be able to use that move, or how you would counter it. Ask them what little adjustments they made to make the technique work.
6) Your cardio is important- You may know a lot, but you will not be able to express it well if you are worried that you are going to run out of air. You can really open up your game and keep pressure on your opponent if your lungs can handle the constant movement and explosiveness.
7) Drill - Although it is boring, many of the best guys I know devote a portion of every training session to drilling a basic movement with a partner. The key here is to make sure it is a BASIC movement you are drilling.
8) Finally, share your tricks with anyone who asks. As they get better, they will be more competition for you. When you have tough competition, you will inevitably get tougher to beat yourself.