One withdrawal strategy that was of interest to me is approach taken by endowments like Yale that combines the 4% inflation adjustment rule with a fixed percentage. Rob Berger explained it recently on a podcast and the FI calc website also has a good description and formula. It might be nice to be able to modify some of the inputs though:

“The Endowment Strategy is used by Yale University to determine its annual spending of its endowment. It was developed by a team of Yale’s economic professors working with the University’s endowment officials.

The Endowment Strategy has many desirable attributes: It responds to market conditions, unlike the Constant Dollar strategy itt responds smoothly to market conditions, so that year-after-year changes to your withdrawal are small, unlike the Percentage of Portfolio strategy. It has an extremely low likelihood of exhausting your portfolio, even over long retirement lengths. The Endowment Strategy is designed to ensure that your portfolio lasts for a long period of time. If your goal is to leave a large legacy, then this may be appealing to you.”