How to write text messages on cell phone?

◆携帯メールの入力方法は？
How to write text messages on cell phone?

I don’t use smartphone, so I just enter normal way.

I like to send an e-mail rather than call from the cell-phone.
I know speaking is easy and first, but I don’t want to bother the other side.
It’s not need to worry about the time, either.