Let your platter not be more full than what you could take in. Take 1 or 2 courses at a time.
Have a fixed study time just as like we have it the universities ans stick to the schedule. Most of these courses demand 5-7 hours a week. Don`t watch all the 5 lectures at one single stretch. Watch only one video per day and understand the indent of it.
Take notes as you watch the lecture. Pay utmost attention to the lecture as you would do in a traditional course. Sign out from G talk, Facebook and all the other distracting features such as ad`s in the sidebar. Keep all browser tabs closed except the one that is needed. Needless to say, avoid distractions at home/office and keep your cell phone in silent mode.
Participate in the discussion forums. Involve yourself in these discussion forums. I made many friends from many countries through the discussion forums. Ask your questions here, answer other students question. Be kind of others. I have seen lot of rude dominating activities in these discussion forums. Refrain from these kinds of activities and keep in mind that the professor keeps a eye on the discussion forums. Discussion Forums are meant to help others, so keep it clean.
Try honestly to solve the assignments. Here is a warning : If you go through the discussion forums, you will find the answers/solution tips, but avoid doing this. Only if you could not answer/dint understand the questions, go to the discussion forums. The objective is learn by doing, not learn by copying.
Tell to your family, friends and colleagues that you are taking a course. Put it up on your social media websites. This makes you accountable and answerable, hence, you would stay focused on completing the course.
Don`t do the course just for the sake of certificate. The certificate is just a piece of paper and has no real value in market or it will not help you get a promotion or increase the value of your resume. So, focus on learning concepts rather than certificate.