My biggest struggle was time management/balance. When I worked from home, I found it very hard to stop working and focus on other things. As for the friends piece, I think the best thing you can do is be firm -- make sure they are clear on the cost upfront before you do the work, and provide them with an actual invoice at the end. A good friend should want to support your business, not expect you to work for free. Good luck!
Thank you for the input. Time management is pretty big, I get lost in one project when I need to take a break.