Wrist curl question

I do wrist curls 3 times a week. I sit on a bench, put my elbow on my
thigh, use the other hand to hold the elbow in place and lift the
weight up and down with my wrist. Is this the best way to do it? I am a
computer programmer and computer work is my life, my profession. I
don't want to do anything to hurt my wrists. Am I doing this right? I
would appreciate any suggestions on building this muscle.