Something I've noticed I do a lot and probably everyone does, good or bad, is have lazy aim. Dirty Bomb revolves a lot around how good you can strafe and shoot while you do so. However, aiming while you move is often accomplished by just slightly varying your crosshair placement and letting your strafe do the brunt of the work.
This is a really bad habit,
and since you do anything like how you practice, don't develop lazy aim.
You should not expect strafing to point you to the target, instead, point to it yourself. Just taking the time to really think about where the enemy is and making the process of tracking their face something you actively consider and not a sort of automatic see an enemy, shoot an enemy action helps out tremendously.
- Running into someone who believes in the tradition of mashing A or D and not both and then proceeding to follow him in a linear trajectory like two ships from the pirate days exchanging broadsides. This means you are putting strafing and aiming into one thought process.
- Landing inconsistent shots against light mercs at medium range. 80-90 HP mercs are indeed a pain to hit, but their speed is probably least felt at medium range where their hitbox is still somewhat large and their movement across your screen isn't that ridiculous. You may just be leveling your aim at their general head level and trying to just peg them once their strafe crosses yours. This is sacrificing a massive amount of your DPS.
So in summary (and tl;dr), don't strafe to aim, strafe to dodge bullets and aim to kill.