While I'm taking a bath...

I like taking a baths.

Most of Japanese take a bath everyday instead of having a shower. Although, I like traveling around the world, I miss the bathtubs very_much. Some countries think our costum custom is strange and it wastes water too much water.  HoweverNo matter, I still like taking a bath.

I Put some bathsalt. Stir and steer it, then before easing oneself  dive [wrong word to use.  It implies fast action and without thinking.  Dangerous.  It is a bathtub, not a swimming pool! Also you are trying to describe a relaxing and a luxury of leisure.  So don't use any word that conjure quickness]into water. It is absolutely amazing!

However, I don't want to stay in a tub idly inactive. My favorite way activity/thing is to chatting on Skype while I'm taking a bath. [Understood!] I wrapped waterproofed my iphone by water proof wrapping it in a plastic bag... And hold it carefully!

It's What a beautiful way to spend a time in a bath. Not only I can I cleanse myself from the daily grime, I can and learn different languages and cultures one at the same time.

Let's Try it! in a this situation. [What you wrote implies you are inviting another person into your bath!]

However, don't Be careful! Not to spend too much time, or you become a prune feel dizzy. [Unless the water is extremely hot, it is not a health issue.]

While I'm taking a bath.

I like taking a bath.

Most of Japanese take a bath everyday instead of having a shower.
Although I like traveling around the world I miss bathtubs very much.
Some countries think our costum custom is strange and it wastes water too much water.
However, I still like taking a bath.

I put in some bathsalt and steer stir it, then dive into the water.
It's amazing!

I don't want to stay in a tub inactive in the tub.
My favorite way thing to do is chatting on skype while I'm taking a bath.
I wrap my iphone by in a water proof plastic bag and hold it carefully.

It's beautiful way to spend a time in a the bath.
I can clean myself and learn languages and cultures one time all at once.

Let's try in a this situation.

Be careful!

Do not spend too much time in the tub, or you will feel dizzy.
(You can also say: Be careful not to spend too much time in the tub, or you will feel dizzy.)

I like taking baths too!
In my house, we don't have a shower, so it's the only option for my family and I.
I listen to music when I bathe. :)

While I'm taking a bath.

I like taking a bath.

Most of Japanese take a bath everyday instead of having a shower.
Although, I like traveling around the world I miss bathtubs very much.
Some countries think our custom is strange and it wastes water too much.
However, I still like taking a bath.

I put in some bathsalt and stir it, then dive into the water. (You could also say, I stir bathsalt in the water and dive in.)

It's amazing!

I don't want to stay in a the tub inactive. (You could also say, I don't want to just lie in the tub.) 
My favorite way activity is chatting on skype while I'm taking a bath.
I wrap my iphone by in a waterproof plastic bag and hold it carefully.

It's a beautiful way to spend a time in a bath.
I can clean myself and learn languages and cultures one at the same time.

Let's try in a this situation.

Be careful!
Not to Do not spend too much time, or you feel dizzy.

The last few sentences could be connected like this, (Try it but be careful, if you stay too long you will feel dizzy.)

While I'm taking a bath.

I like taking a bath.

Most of Japanese take a bath everyday instead of having a shower.
Although, I like traveling around the world I miss bathtubs verymuch.
Some countries think our costum customs is strange and it wastes water too much.
However, I still like taking a bath.

I put some bathsalt and steer it, then dive into water.
It's amazing!

I don't want to stay in a tub inactive.
My favorite way is chatting on skype while I'm taking a bath.
I wrap my iphone by water proof plastic bag and hold it carfully.

It's beatiful way to spend a kill the time in a bath.
I can clean myself and learn languages and cultures oneat the  time.

Let's try in a this situation.

Be careful!
Not to spend too much time, or you feel dizzy.