"I use a cannister garden sprayer for applying liquid broadleaf weed
killer. Just avoid doing it before a rain. It's quite a bit less
expensive than powders, little is wasted and there isn't a runoff
problem. "

I agree. It's less stressfull to the grass, far less harmful to the
environment and more effective on the weeds. IMO, the only time weed n
feed is a good option is when the lawn is really full of broadleaf
weeds due to previous lack of control.