Last of us unfortunately has very poor aiming mechanics (to be honest movement mechanics in general. It drove me mad). It's going to feel shit no matter what you do. Other than that, using a controller you 'aim' with both sticks. Turn to targets with your right stick but make small corrections left and right with your left stick. Different games have different types of aim assist but the main two slow down your crosshair when moving over targets with your right stick, and the other turns you to stay on targets when strafing with your left stick. You want to abuse the latter as much as possible. Set your sensitivity on the lower side of middle, not so much that you feel like you're turning in treacle (though again, LOS is shit for this and will always feel naff to some degree), and practice.