Depends on the character I'm using too be honest, for example.
When I play karthus I tend too play very aggressively but at the same time I always watch for mia's, cool downs on the other persons skills and my own hp vs their damage.
When I mid as say...morgana however, I land my skill shot and kill them. then kill anyone else who tries too gank me without really paying attention.
And I'm not saying one is op or the like, just morgana kinda plays herself after her skill-shot, so it involves less thought on my part.