In my opion, the best practice to learn about the tips and tricks in Adobe Illustrator is to learn through how-to tips ans tricks tutorials.
In this post, Some of the most amazing Illustrator tutorials and vector art tutorials that will help you get idea about how to use each of the Illustrator tools and features. There are also another amazing collections of Illustrator tutorials here:
Learn how to create cartoon character from scratch in Adobe Illustrator. This tutorials goes through the process of creating this nice character from the step zero on paper till the final step on Adobe Illustrator.
This unique tutorial is one of the unique tutorials that teaches how to create an illustration of a ship based on a real diagram of a real ship. If you like to learn more about creating vector ships, I recommend starting with this great one.
Rafiq Elmansy is a graphic designer and runs his own design studio Pixel Consultations. He is also an Adobe Community Professional, Certified Expert and Adobe user group manager. He is a Friend of Icograda (the International Council of Graphic Design Associations).
You can read his writings on Adobe site, Adobe Edge magazine, communitymx.com and his own blog www.graphicmania.net. He can also be followed on Twitter @rafiqelmansy