I use foam rollers when working with oil. And I brush the paint out after. Being that I'm Brushing, I use the roller to quickly apply paint, not worrying if I get full coverage. I roll out the top half of door first, then brush it, then roll bottom half and then brush. If i try to roll the whole door the paint begins to set up before i finish brushing it out.
My brush stokes are aligned as would be the grain of the wood of the door, or how wood would go if the door was wood instead of steel, or fake wood grain.