Want to improve Vocabulary. You should make a sentence with that words. And practice pronouce with those words.
Grammar. You should review on each day and make a sentence with that grammar.
Reading skills.You should spend more time to read a news by English or read an English story book , novel.
Writing skill. Writing some familar topic and make sure you apply with sure grammar and don't forget a topic sentence.
Pronunciation. watching Khanh Vy offical or some england, America blogger. And searching new words you had write in the school on Google Translate to hear how to pronouce that.
Speaking. You should read again your sentence you make with vocabulary.
Listening. You should watching IELTS-FACE OFF on VTV7 to listen tho their conversation.