Something that cannot be understated is setting yourself up with a work environment that motivates you. Personally, I know that I have some trouble consistently being productive and meeting my own deadlines if I am completely isolated. When surrounded by talented like-minded individuals (from any discipline), it's a constant source of inspiration to keep on going.
Being self-funded, it may seem like a waste of money to rent a workspace when you could theoretically work at home (especially for a one- to two-person team), but to me it's a fundamental tool in keeping the project on track. Of course, it should be financially reasonable; it's not the wisest move to go full on fancy pants with your office space. It helps if you can find a group of peers, colleagues, or friends working on similar goals and you can split the cost of a workspace that fulfills your most basic requirements. For me, this includes space for a desk, wifi, and good people. At first I was looking for a nice coworking space, but there doesn't seem to be any options around Pasadena, California (yet). However, I was fortunate enough (perfect timing) to find a close-to-home location with former game dev workmates, friends, and some new faces. It's in the heart of a commercial district with plenty of walkable food for
Home music & audio production studio
It works out perfectly for me as I now handle music and audio production at my home studio, and most game development at the office. Google Drive and Dropbox are my best friends in this scenario, and I'm currently using Git for version control and syncing my Unity project and game assets with Bitbucket. This allows me to pick up where I left off on any part of the project (graphics, code, audio, etc) on my work PC and home Macbook Pro.
While it is certainly feasible to be very productive in a "bubble" – and I know many people that excel at this – it's good to self-evaluate your own tendencies and put yourself in positions that are conducive to the way you operate. For game development in particular, it's also healthy to receive periodic feedback when you have something new to test, or a gameplay mechanic idea, or an art test – but make sure it's from intelligent people you trust who are just as likely to point out shortcomings in your game as they are to offer praise. You don't want to be delusional about the merits of your project until it's too late!