Wow NEKS! Just read this thread and what an inspirational story. Congratulations on your success, and I admire your determination.
I consider myself in a similar situation that you were at one point currently, however I have no aspirations of starting a tree business. I have another full time job that is completely unrelated to trees, however I am a fairly serious woodworker on the side and took the plunge on tree climbing as a possible means to acquire more wood to work on (being able to offer someone the ability to prune etc. in exchange for the wood), and a semi-obsessive drive to maintain my property and everything on it myself. Furthermore, I try to ensure all "hobbies" (activities that are not my full time job) which require expensive equipment at some point pay for themselves, and hopefully at some point generate a little extra cash.
Long story short, as it did with woodworking, shortly after friends, co-workers and family found out about me working on my own trees, I gradually started to get requests. While fulfilling some of those requests, neighbors/friends of the people I've done work for have inquired about potentially getting me to do some work for them and the question that comes up constantly is whether I'm insured (for tree work). Obviously, I'm not and I haven't even looked into it because I don't have a company and have only done work for favors and/or other things.
Let me be clear about a few things: I don't plan on making this into a long term business, I don't plan on advertising (don't want to undercut, no pun intended, professional arborists in the area), and I would never take on a request that I didn't think I could do, or was potentially dangerous to myself or anyone's property. I would however like to help folks out that are in my immediate circle (and perhaps just outside) that may feel a little squirrely about hiring someone they don't know for a job that probably should be done that may not really need to be done. My assumption, perhaps naively, was that people would overlook the standard business practices (insurance being one of them) in exchange for a much lower price that comes with the lack of overhead.
With that being said, I'm curious how you (early on) and others dealt with (or deal with) doing work uninsured on other people's property. Obviously this hasn't been a huge issue for me doing work for only folks I know fairly well, but I've been getting a lot of interest from neighbors recently and am not sure how to deal with it, other than doing it for free. My general rule of thumb is to do things for free or a massively discounted price for people in my immediate social circle, and then charging something more realistic to referrals or people who ask. That's one thing with turning a bowl or building a cabinet, but I don't have to tell anyone here that tree work is a bit more dangerous and physically difficult to do.