While I've never attempted any 1/800th scale decals (my venue is mainly 1/48th), I use a sewing needle chucked into the handle of an X-Acto knife to move tiny decals into position along with a magnifying lens/lamp, a steady hand and a lot of patience. To blot up the excess Micro-Set or Micro-Sol the decal is setting in I use a 5-0 brush and a tiny piece of paper napkin.