[EddieRingle]

I never really considered this an issue. I've been self-employed since 2012 and kept a spreadsheet that calculated the quarterly payments I need to make, so I just sent that amount into a 1% APY savings account every time I got paid.

More recently, I took on a regular W2 job, and I've updated the spreadsheet so that it accounts for both W2 income (and any withholdings from that) as well as 1099 profit/losses (as I enter business expenses as well).

It was all pretty easy to set up and I just update it whenever tax brackets and standard deductions change (usually an annual thing).