You can write an informal letter to your friends,family members and so on.
Informal letter are easy to write: friends and family members do not think much about your grammar.
In informal letters you can use contractions (I’m,you’re,she’s;I’ll;I’ve, he’s) and informal language like ‘I luv you’.
You can start with ‘Dear Lisa’,’My friend’ or anything you want to start with.
You may end with ‘love’,’best wishes’,’lots of love’.
An Example of the Informal Letter
Dear Lisa
How are you? I’m very well.I’ve a good time with my friends here.My brother has a new girlfriend and my sister’s a new job.How about you?
Please, write me soon.
Love
Anne