Preschool and kindergarten children really work hard on creating, identifying, and extending patterns. Even adults do this, to a great extent. Think about the pattern you notice in your checkbook when you go to Starbucks too often or the pattern you notice when your child doesn't get enough sleep.
Patterns are everywhere. Help your child recognize, create, and extend them.
Find patterns in your house. Go on a "pattern hunt" and try to find patterns on clothing, blankets, painting, games, etc.
Create a pattern. Gather objects of all sizes (buttons, coins, water/soda/juice lids, pasta shells, etc. and make a pattern.
Describe your pattern to your child and let your child describe his/her pattern to you.
Create a pattern and have your child extend it (or continue the pattern for you).
Extend your child's pattern.