I have liquid rosin. Its pour-able but still has a bit of tack to it. A small paint
brush puts down a film rather than a puddle. I don't use it all that much.
Generally I use my Kester 44 rosin 63/37 and the SMT parts I find my larger (1/4")
tip Weller easier but there is a lot of technique and experience. Been doing SMT
for a few decades. I do hate the 0402 parts though, I wear a dust mask so I
don't accidentally blow them away breathing.
Biggest thing I see keep the iron tip clean, do not clean it before replacing it in
the stand, clean when you go to use it, and put it back dirty. Putting it in the stand
clean allows it to sit there and oxidize, it will be harder to clean then. I've told people
that and then videoed them doing exactly the opposite.