When you're working out for the purpose of building muscle, it's important to consider how much protein you're taking in. The body uses proteins for many things besides building muscle, so if you aren't getting enough, you may not see the muscle growth you want. Make sure to avoid this by eating a diet high in proteins.
Try varying your grips. Once you become experienced in working out, your muscles will start to resist any growth on exercises that are familiar to them. Different grips can help to make these familiar exercises different, which can cause additional muscle growth. Examples of exercise where you can change the grip are barbell rows, barbell curls, pull-ups, and bench presses. Try using wide grips, close hand grips, reverse grips, and even mixed grips that include having one hand up and one hand down.