I recently talked about when to increase weight and I said when you can get 6 reps on your own with good execution it is time to bump up the weight. How much do I increase you may ask?
When moving up in weight, keep this tip in mind. You always want to increase weight by the smallest increment possible. If you are using a barbell that typically means 2.5 lbs per side. If we are talking a cable machine or dumbbells then use the smallest increase available.
Your body will be able to accommodate these small increases better than bigger jumps in weight and thus it will help your strength progressions keep moving forward without hitting a plateau.