there is not much to do

hold solder tip(clean and with a bit solder sticking to it) on the part you want to solder
optional add some flux to the parts, sometimes the one in the wire is not enough
add solder in form of a wire with flux core
see when the solder is molten and has both parts covered
remove solder tip
done

the most important thing is to have a good solder tip on the right temperature,
if its crappy or totally burned and oxidized and too hot it wont solder good
and the solder wire should not be too thick or thin