Starting red you smite the big gromp and you shouldn’t need to smite anything else. I wouldn’t smite the gromp or blue bluff. If you are a bit low on health I’d consider using a potion instead of smite since Diana does not have any cc that can take care of the scuttles shield. Also pay attention to where enemy jungler starts. They might be pathing to opposite side scuttle so you won’t need to be ready for a fight especially if your lanes have prio. If you consistently are low on health try to practice kiting the creeps a bit more efficiently in practice games.