Watching how forgiving solder can be, and me still being bad at it is blowing my mind right now.
Really. Just add more flux than you think it could possibly need. The biggest failure mode I've seen with solder of all kinds is not enough flux.
This Amtech no-clean is really gooey[0], but pretty useful for rework.
This Kester water-soluble is incredible, but needs to be washed[1].
If you need to hand-clean PCBs, a small photography developing tub and a sonicare (or similar) toothbrush is a game changer.
Today, I won't even plug in the iron if I can't find my flux first.
Hey kids - don't listen to the old geezers (though I'm one too). Get lead-free and figure it out. It's really just about getting in reps, and caring about the results.
In my personal experience, leaded is maybe 5% easier.
If you're doing hobby level work, it is definitely not worth having lead around getting into and onto your other stuff and possibly being licked by kids or pets or whatever, and turning your projects into hazmat.