Suggest giving full details, three strategies which parents may use to encourage their children to communicate with them

A parent could suggest family dinners, restrictions on phone use while in the house, or journaling. 

Family dinners: This method would encourage open conversations with the family about everyone's day, or just establish more comfortable lines of conversation with everyone. 

Restrictions on distractions: This could apply to phones, tablets, tv, or anything like books that a child was using frequently and/or in a manner of avoiding conversations with their parents. A time limit or allotted time to use these devices could be set up to encourage more talking or time spent with parents.

Journaling: This method could be used for letting the child communicate their thoughts by writing them down if it is uncomfortable to speak to the parent still, or they have trouble with conversation. However it is important in this situation that privacy boundaries are clearly established, like whether or not the parent can read certain entries of the journal, or if one journal should be private, while another can be read aloud with the family, etc. This will encourage a supportive and trusting environment that is essential to opening lines of communication.