Construct a routine. Start with what you can do for 10 reps then move up maybe 10 pounds and drop down to 8 reps, then 6 and 4(maybe even 2). I do that with bench, other lifts I just do 3 sets. It's pyramid building. Then try moving your starting weight up maybe 5 pounds, if that doesn't work try doing the starting weight for 12 rather than 10 reps or change your routine a little bit if you've totally plateaued.
