How do you empty your bladder?

I have been wondering how others are emptying their bladders. Many of you are much more experienced with this than I am so, I figured I would see how others are emptying their bladder.

I am not sure if I should squeeze my bladder until the last drop dribbles out or if I should just keep it open and let it happen naturally. Do you hang it upside down?

I usually keep it up in the air and squeeze my nipple, then turn it upside down and just let it hang. Is this common? I don't want to get moldy or gross.

I admit that I am new to the hiking gear and am not all that familiar with proper maintenance. This is just one of those things they seem to overlook. Your advice is appreciated!