Student or Learner
how to write good English without extending its length.
Note that I have corrected the errors in your title. We don't start a question with "How to" but we do end a question with a question mark.
I have also corrected the rest of your post for the same reason.
Always start a sentence with a capital letter.
Why don't you give us an example of a sentence you have written that you don't think is short and effective, and then we can have a look at it?
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.