As I mentioned before, I am rarely asked for recommendation letters for professional work, either from students or from those hiring. The industry tends to work more informally with that. BUT if you want to go to grad school, those letters can be critical. From what I've seen, they can help a borderline applicant get in or elevate someone who otherwise wouldn't be considered. Realize that not all teachers will write them for you. I only will consider them if a student got an A in a class of mine or was exceptional in some way, and I have turned down people. I once had a B- student from a class 2 years earlier ask me. There's no way I could write a strong one, so I didn't write one at all. For people who work after school, sometimes you can use a mix of school and professional people to write them. What does this mean? If you want a good letter, you may have to impress someone enough to write it for you. If not, your application may be at a severe disadvantage. So what do you do? You have cultivate a relationship with people. Networking.