Try doing different exercises as well. Vary the exercises that you DO do by changing position, angles, etc. Remember that you don't need to be 'traditional' about training.
You need to know that you are training for something and that what you are doing is going towards achieving a goal. Make one and then work your training to suit that.
And if you have been training too long without a break then I suggest that you take one. You should have at least a week off resistance training every 8-12 weeks to give your body a chance to recover.