The best way to do this is emulsion the ceiling and Walls first(cover all the big areas first) you usely need to have 2 coats. Then finish with your gloss by cutting it into the emulsion. Sorry should have told you to make sure all the areas are free from dust, above doors and along skirtings. Hope this helps.

Do you paint the walls or woodwork first?

Many homeowners paint the walls first, then move on to the trim while they wait for the first coat to dry. Homeowners should think more strategically, says Rich O'Neil of Masterworks Painting. "Paint all the woodwork first—the first and second coats—then move onto the walls," says O'Neil.

Should I emulsion before gloss?

emulsion will set faster than gloss (gloss takes a week or so to fully harden) so when you come to remove the emulsion from it, it will ruin the finish. i always emulsion first.