Just as with your first strength workout this week, challenge yourself by increasing the reps or weights today. Just because you've done these movements before doesn't mean you should be getting too comfortable. If it feels too easy, it is too easy!
Keeping a written workout log can help you keep track of your workout volume. Record the weight used and number of reps, of course, but other factors such as mood, diet, and general energy level are worth noting as well.