I FIREd this year at age 56, so the rule of 55 is perfect for me.
The main strategies I have seen:
1. Take your lumps with the 10% penalty. It will only be for a couple years, and you should be in a low tax bracket, so it will not be all that bad.
2. Use the equal payment withdrawal. Downside is you need to take the withdrawal until you reach 59.5, regardless of how your life turns out. If you stop, all withdrawals becomes penalized at 10%. The CFP's I have talked to have steered me away from this, because it is very easy to get it wrong.
3. Get a job for a year. The timing is to qualify for their 401k the calendar year you turn 55. There is usually a delay in qualifying, so you can likely start the job at 54. It needs to be a contract or standard W2 job so you qualify for the 401k. If you cannot find something in your field, try librarian, Barnes & Noble, supermarket, or big box store. You only need part time to get the bennies in many cases.
I like #3. I found a full time job in 2011 at age 49, and kept it for 7 years until I quit. We hired a Chemical Analyst aged 66 while I was there. Unless you are unskilled, I think you can scare up work as long as you are willing to look for 6-12 months or take a menial job. "I tried retirement, and I did not like it," plays surprisingly well, even if you don't really mean it.