Monica C.

Get your children to read aloud from English storybooks. A word of caution - choose books that are unabridged because often such books are rewritten, and the level of language is not upto the mark.
Have conversations on daily happenings at the dining table and get the child to participate in the discussion.
Play guessing games like - Who am I ? or Twenty questions to help practise making questions.
You can also get your child to make presentations on a topic of his choice and present it in front of the class. At the end of it, ask your child questions and get him to answer.
You could use google maps to ask, practise asking and giving directions.

Communications skills can be developed with practice. Communication can be both written and spoken. For developing sound written communication skills, you need to follow the rules - e.g. you need to know how to write a business email. Also, having good grammar and vocabulary will help you write effectively and express yourself.
For spoken communication, you need to speak English regularly. While you might feel you do speak English, if you observe yourself, you will find that you lapse into your mother tongue whenever stuck. Fluency can be achieved with practice, especially with someone who has a good command of English.