How are you ? ... if you want to improve your writing skills you have to increase your vocabulary ( without words you have nothing to work with ) , and you have to study grammar so that you will be able to build right sentences , then you have to practice every day . Write in English everyday , just simple sentences .. after that try to write about specific topics , start with easy topics like introducing your self , talk about your school, describe people , places , your hometown ,..etc .
Also text chat will help you . Above all this you need to set your time ( don't spend much time chatting , just 1 hour is enough I think ) .Let me tell you about increasing your vocabulary , the best way is by reading .. there are many ways to do that , you can read short story ( don't be shy to read kid's stories sometimes it help ) or you can search about the topic you want to write about then take notes , write the new vocabulary , and study it .. after that try to write by your self .
Remember : Learning a language needs patience and time .
The more you read ,the better your English will be .
The golden rule is Repeat .. read more than once .
Best Wishes :)