Necrons are top tier in small games thanks to reanimation protocols having a chance to shine, so lean into that. Definitely pack at least 1 full size unit of Tesla Immortals with something to My Will Be Done them to deal with hordes. 6 destroyers are durable, reanimate, and give you anti tank fire. Tomb Blades are fast, hard to kill, pack a punch, and reanimate. If you have any spare points scarabs can be useful for unknown opponents just to soak up the first turn of smite against psyker heavy armies. You can try to sneak a Doomsday Ark into the list if you think you'll run into lots of armor but with destroyers in your list its not necessary at 1000 points.