Roth conversions are best done piecemeal in lower-tax bracket years, and investors should pay the resulting taxes out-of-pocket rather than using retirement funds.

“I'd like to suggest to most people is once I retire and I don't have my salary, my paycheck coming in, that's maybe I have to already claim taxes on, we call it kind of an income valley, where it's between I just retired, so I don't have the paycheck anymore, but also maybe in 10 years, I'm going to”