How can I effectively perform contraction curls to target my biceps?

To effectively perform contraction curls for targeting your biceps, start by holding a dumbbell in each hand with your palms facing up. Keep your elbows close to your sides and slowly curl the weights towards your shoulders, squeezing your biceps at the top of the movement. Lower the weights back down in a controlled manner. Repeat for the desired number of repetitions, focusing on the contraction of your biceps throughout the exercise.