How to Unclog a Bathroom Sink Drain

Every 4-5 months our bathroom sink drain gets clogged. 
Considering I have 3 daughters, as well as myself, who all have long hair, as well as a teenage son with thick curly hair; I guess I shouldn't be surprised. 
It seems no matter how many times I tell my "wonderful" children to, "Not cut their hair over the sink (and not pick it up,) or if there is hair in the sink, "Take it out of the sink and throw it in the trash.
So I end up with a sink with water that won't drain.

My non-draining sink.
After wasting a lot of money on drain cleaners that claimed to unclog bathroom sink drain from standing water, I took the hands on approach to unstop my bathroom sink drain.

This is underneath my bathroom sink cabinet. This time around I get the added "bonus" of mold, ugh.

The first step on how to unclog a bathroom sink drain is to put on gloves. 
Because that gunk that is going to come out is really gross. 
Now, turn off the water under the sink. 
There will be two medal knobs, turn both of them clockwise until they won't turn anymore. 
You will also need an old container of some sort, one that you'll be throwing away.
I used an old creamer container that I had (re-purposing. :) 

Next up, twist counterclockwise until the white (screw) part separates from the other piping. As seen above.
Do the same thing with the one in the back, until it releases the pipe. 
Be careful here, you want to make sure to use your free hand (not turning) to hold the pipe so that it doesn't fall. 
Now slowly take the pipe, and dump the contents into your container; then put the container under your pipe (as seen in the picture below.)

This may unclog your bathroom sink drain.
Unfortunately for me, it did not. 

Next, turn the small pipe counterclockwise until it comes off of the other pipe.

I had to get a large wrench to loosen up the metal part at the top of the sink (see pic below.)

Once I loosened it enough to be able to turn the pipe around towards me; I was able to remove the metal bar with the ball attached. (See pic below)

This "ball" can collect a lot of hair, and a lot of times after you remove it, you'll have unclogged your bathroom sink drain. 

For me, it didn't unclog my drain; it did release some trapped water into my container.
What I did at this point was to completely remove the metal bar, and pushed it through the drain hole in my sink. 

Finally, I figured out how to unclog my bathroom sink drains! As you can see the "lovely" culprit in my container, lots of hair!

Now, you're just going to put everything back on the same way you took it off.

Start by putting the "ball" back into the hole, and then turn clockwise until it is tightened.

Make sure not to over tighten because it'll be hard to get it off next time.
(Believe me, I know ;)

Take your pipe and put it back into the pipe sticking out of your wall, and tighten the white moving part until it's snug. (remember, not too tight) 

         Finally, slide the top pipe into the large pipe, and tighten it down.

So there you have it; The best way to unclog bathroom sink drains. (in my opinion of course. :)
This is also one of the best green ways to unclog you drains; no harsh chemicals, safe because you're not toting pans of hot boiling water to your bathroom sink.
 I hope I helped you figure out the dilemma of how to unstop your bathroom sink drain for good!