The wife and I pay via a combination of W2 withholding from our respective corporate job and also write paper checks submitted via quarterly 1040ES payments. Having dealt with the IRS and claimed missing payments in the past, for anything outside of W2 withholdings I want copies of cashed physical checks in case there is a dispute.
We try and pay in enough throughout the year to cover the tax obligation for the year so that we don't have penalties/interest pile up if we underpay, as we almost always have to file an extension given that we never receive all of our K1s prior to tax filing day.
For 2021 we have paid in just shy of $200K between withholding and 1040ES payments, and I am hoping that we don't owe more than another $5K on top of that. I would be ecstatic if we didn't owe anything more and/or even got a couple grand back.