It’s better to get ready early. Build and expand your network in relation to the program that you want to apply for. Or generic professional relationship is also fine. If you are lucky, you may not only find someone to ask for a letter of recommendation, but also a mentor.
It’s pretty common to ask your teacher or professor for a Letter of Recommendation. But depends on your country, they may not be as familiar with the process as professors from the States – be prepared to explain and clarify what you are asking for.
You might need to be somewhat lucky to have a boss or co-worker that you can be open about going back to school and ask for a letter. If you do, they are great source of recommendation to show your potential as a professional.
You may want to explain how you may be able to become better at your work or contribute to the company better after the program, regardless of whether you want to keep your job or not.
3. Volunteer work
Depends on what kind of volunteer work you do, you might be able to get a letter of recommendation from someone there. Obviously, it would be better if that ‘someone’ is a professional, who is working in same or related field.
4. Other personal relationship
It’s not ideal, but you may also utilize other kinds of personal relationships to get the recommendation. Make sure not to make it too personal, and have a good reason to get the letter from that particular individual.