I decided to update my tutorial about creating seamless pattern in Illustrator and add few other ways that may be more convenient for you.
For those of you who have Illustrator CS6 or CC there is a good news, the process of creating seamless pattern became automatic, so now every beginner can solve this task easily. Just select your object and click on Object>Pattern>Make. When you do so, your objects will automatically transform into a pattern and the Pattern Options dialog box will appear. When you look at the Pattern Options dialog box you will see many options - try them and change until you get the result you want.
For those of you who have Illustrator of earlier versions - I'll tell now few ways and tools of creating pattern.
The first way
This way is perfect especially for easy patterns consisting of few objects.
Here is the final pattern we will receive.
