Learn about What is an Informal Letter and its Format , Samples. Know Tips for drafting a Good Informal Letter and also explore various topics examples. Learn how to write an informal letter in English with a casual and personal tone. See the format , examples and tips for addressing, greeting, writing and concluding an informal letter . Letter Writing in English. Check out what is a Letter , types of letters , tips to write good letters , solved examples of Letter writing in English. Format for Informal Letters – Letter writing is a valuable skill to cultivate. Written communication is essential in both formal and personal matters, so letter writing skills must be developed. We will concentrate on how to write informal letters effectively and how to improve our efforts in this article.