Improve learning skills
Short answer 

Practice! 

Long answer Practice (smart)! The more time you spend being a student (studying, reading, summarizing, asking questions, taking notes, and pursuing answers) the better you will become at being a student. For more specific tips, check out this article by Scott Young. He focuses on methods that allow you to study smarter rather than harder. The key to this is to recognize that all knowledge is interrelated; everything connects to everything else,  and therefore no learning is wasted. I find his tips and hints to be useful, though I cannot learn quite as efficiently as Young claims one should be able to.