What is the proper way to use a citrus press?

I'm curious, could you please elaborate on the proper usage of a citrus press? I've heard it's an efficient way to extract juice from citrus fruits, but I'm not sure if there's a specific technique or steps I should follow to ensure optimal results. Could you guide me through the process, from preparing the fruit to squeezing out the juice? Also, are there any common mistakes to avoid when using a citrus press? Your insights would be greatly appreciated.