I tried to go pt working for a law firm and it did not work. I ended up working almost ft hours for pt salary just as you described. I, like many lawyers, respond to high pressure to get things done and I could just not turn it off without feeling guilty.
What has worked very well for me is setting up my own firm. I have no pressure to anything I don't want because I'm the one who has the consequence of this. It also allowed me to reduce overhead and take specific project that I am interested in on. I earn much more per hour this way even though I am priced below my level of call at a big firm. In my case I work from home or the client's office so I need no office space.
I recommend developing a niche of some kind that makes you valuable to clients. Things that I know of that work well for this include tax, high conflict divorce, and estates. I'm sure there are many others.
I have thought about this. I'd be interested in hearing more about how difficult it was to make the transition, particularly setting up all the administrative stuff that is necessary for doing it. I think my field -- patent litigation is probably sufficiently valuable that I can still get clients.
The admin stuff was not difficult. There are loads of online guides on what is required to set up a business. In addition, my provincial law society has a guide and some online courses that count as PD hours. There are some books published on how to set up a law practice as well.
As far as admin goes, I'm in Canada so it won't be exactly the same but generally you need to reserve the business name, register and get your business number, same for tax number, Westlaw/Ecarswell if needed, Quicklaw or other accounting/time tracking/billing system.
Once you have a business number you can set up a corporate chequing account. You may also need to set up a trust account if you take retainers. I did not for a bit but have one now as I hold funds in trust for clients for other purposes. The trust account has some strict accounting and reporting rules. Also, I did not incorporate right away as there is not really good liability protection for lawyers as we will be held personally liable for errors and omissions and that is covered through professional insurance. Incorporation in Canada really only makes sense after you net over $100,000.
Other than that, you need to do the annual practice declaration with your law society for your own practice which is slightly more detailed than as an employee. You need to demonstrate that you have set up the systems and are following them (with a checklist).
You might need a bookkeeper, I have one.
You know what the hardest thing about the transition was? It was breaking my feeling that I had to sit at my desk in my home and be there for office hours even though I was working part-time. It took me a long time to accept that, with a cell phone, I can be anywhere and respond to clients.
The truth is that I made no more money and gave no better service by imposing office hours on myself. It probably took a year to believe this. Now I go for walks, shop, volunteer at the school and just answer calls as they come in during the day. I never sit at a desk unless I am at a client's office. I don't even have one. I have a file system and I work from a laptop wherever I am.