And do it with enough solder on the iron to get good thermal transfer. "Enough" really isn't a lot but it's also not a tip that's been wiped entirely dry. How

And do it with enough solder on the iron to get good thermal transfer. "Enough" really isn't a lot but it's also not a tip that's been wiped entirely dry. How you hold the tip relative to the via/component lead matters (because you want the liquid solder to help with the thermal transfer).