Your relationships with professors and staff can make a huge impact on your future. Don't take this step lightly. Start preparing yourself for this step sooner than later.
The goal is to apply basic practices during your college experience so that asking your professors for a recommendation is as natural as possible. Think of it like this: if a close friend and a casual acquaintance both needed your reference for a job, who would be easier for you to talk about?
So where do I start? Fortunately, the process doesn't have to be intimidating. The first thing to keep in mind is that the majority of professors understand that writing letters of recommendation is part of their job. More often than not, they take pride in being able to help their students succeed in their academic careers and understand that students might not know how to best approach them.