For me, overhead 7018 is a matter of making sure the rod is perpendicular to the BM surface, keeping heat low, and I always used a reverse U oscillation holding on the sides to ensure no undercut, just as with verticals, but not holding as long since the molten metal will slip 'down' on you to sag, and not slip back filling in the middle as with a vertical. think aobut the direction of gravity.
You can overhead even 1/4" 7018 but it requires more skill. Until you spent some time with it I'd stick to the smaller rods.
But welding is a skill, there will be other techniques just as valid I'm sure.