grip & set-up, posture, address alignments ball position will all have a bearing on it. first point of call check all these 'statics' to they are in the right ball park. club face aligned square to ball/target line, but body alignment (particularly check the shoulder alignment) shoulder chest hips knees feet are parallel square to the ball/target line.
then how you take the club back, the path you take the club back on will influence the path the club comes back down on to impact. so as you start to take the club back keep top of the upper arms lightly connected to you chest/rib cage as you turn back.
so don't whip the club a ways inside going back flat behind the legs. don't disconnect your upper arms & stretch them away from the body so the left upper arm is no longer connected to the chest as you start to take the club away.
just try to turn back to the top connected, then at top of backswing when your shoulder turn stops make sure your arms/club stop too, don't lift them further back on their own trying to get a longer backswing this will nearly always mean you will start to throw the club & so move the shoulders outwards as you start back to the ball.
start the transition from the lead foot slight pressure into the ground first, so lower body leads the downswing, then the right shoulder turns downwards towards the ground & the arms hands club swing downwards not outwards first off.
as long as you keep your body turning through the motion the club head will then travel from slightly down from inside then move outwards to the ball & through impact, then keep turning it will come back inside & up to the top.
imagine a big inclined hoop that the clubhead moves around your body on.
so in the takeaway/backswing the clubhead goes backwards first off, then inside, then upwards then continues back till the shoulder turn stops, from the transition then the clubhead starts to come downwards first then from halfways down it moves out to & through impact, then after impact it moves back inside & then upwards to the finish.
You could try the headcover drill.
Place 2 headcovers on the ground. The first one foot behind the ball and a few inches outside the ball to target line. Then place another a foot in front of the ball a few inches inside the ball to target line.
The hit the ball without hitting the headcovers.
Been doing it myself recently. My coach said that I was taking the club back too much on the inside which then makes you come over the top when you start the downswing.
Quite simple......try a few slow motion swings and concentrate on feeling your right shoulder coming down under your chin and the club head travelling towards or slightly right of your target. Then gradually build up the speed concentrating on those same feelings.
I was a chronic over the toper. When you get to the top of your back swing try and feel like your left arm is glued across your chest and stays there until impact.
Worked a treat for me