I had the same problem at the beginning of last year. Occasional straight shot, mostly slices with a good amount of distance. This is how I fixed it.
First off, watch a bunch of videos of pros hitting shots. This will put the idea in your head on what your swing should look like.
These are the points I focused on. First off, I made sure my clubhead was outside on my backswing, meaning if you are looking down the line, the clubhead is outside my hands.
Second, make sure I am keeping my left arm straight as well as making a full shoulder turn.
Third, initiate your downswing with your hips, not your arms. Exaggerate this move because you can't really over do it.
At the range I would take tees and make a path from inside to outside. Then I would practice hitting balls through this path. If I hit one of the tees, I knew I was coming over the top. With enough practice you will be duck-hooking shots no problem!
Lastly, don't get mad. We're not pros. We don't have the right to get mad.