What's expected from you
The letter you have to write in A1 is fairly simple. All you need to write are 30 words. You don't have to know any grammar nor a wide range of vocab to pass this part of your exam with 60%. No thinking is required either. All you have to do is to memorize a set of recurring phrases for a limited range of topics.

How to achieve that
In the next step of this course you'll get to know our A1 writing tool. With the help of this tool you will easily memorize a set of possible exam letters which will help you reach the 60% threshold for passing your A1 exam. Simply practice with our tool as much as you can until you have fully memorized all our sample texts.

How to practice efficiently
Whenever you got 10-15mins, use this tool. If you don't delete your cache or cookies your browser should remember which lesson you have been working on. But just in case please always note down where you stopped practicing so that you can continue where you left off when you come back and things don't look as they should.
Depending on when your exam is, and how quickly you learn with this tool, I'd say you should not work more than 30mins on your writing per day.