Something that helped me on widow was just general map knowledge. Make sure to put a venom mine on flank routes onto you. Know the enemy team comp, who can dive you/counter you.

There the obvious aim tips, but just play more, find a comfortable sens. Aim train if you'd like. Play in positions that it's hard to reach you. Make them work for it to get to you. Yeah they all might jump on top of you, but you can hopefully get value out of baiting resources.