A nice texture can hide a lot of defects in your tape job... and it provide character to an otherwise flat wall or ceiling. This video shows the simple way of putting a knockdown texture on your wall. The same technique can be applied to your ceiling. If you are planning on texturing your ceiling, do that first, because you will have overspray on to the walls. You can you use a piece of cardboard about 2' by 2' as a guard, so you can protect areas you don't want to texture. It's good to test you technique on scrap piece of drywall or plywood before you get started.