Jacob, I had a local pro tell me that he made more money correcting slices than anything else.  My first advice would be to find a pro to get some solid advice.  Slices are from an open clubface at impact, pretty apparent, figuring out why your clubface is open is not always apparent.  Sometimes everything seems right and normal when theres some little flaw in there messing things up.  When I start hitting slices I know its one of two things: hitting the ball on the club face too close to the hosel, or my shoulder alignment is left, both leading to an open face.  Those two problems had me frustrated for weeks before I saw my pro, now my pre-shot routine is to set up so that those two problems are not likely.  Your slice cause could be stance, could be grip, posture, or any number of things.  A good pro can spot the slice cause pretty quick, might be worth a few bucks to get a good fix from a pro and end the frustration.  If you're an advanced golfer you might also have someone with a tablet video your swing, you might just see something apparent that needs attention.

I Agree with Allen, go get a lesson from a Pro.  I did just that this past year and it changed my whole game.  I felt like I could play and practice with some legitimacy. We talked about impact, club face angles, stance, grip, ball placement, etc.  I know hit a slight fade with much consistency and my scoring has greatly improved. When I have a miss hit, I generally know what I did wrong. 

Good Luck

Go to a golf retail shop and ask them for a GOOD teaching pro. I'm a plus handicap that battles hitting it to the right also. I think for most golfers its tension in the hands and arms. Forget the "hitting the ball aspect", and focus on "swinging the club". The "hit" mentality almost always leads to an open face at impact.

I agree with seeing a GOOD teaching pro. The pro at my club fixed the slice Id struggled with for years in about 5 minutes with a grip change. With the grip change, he got me drawing the ball, and sometimes fighting a hook. He was able to correct that in our next lesson, and Ive been hitting the ball straight or with a 5yd fade, ever since.

There is nothing comparable to getting someone qualified to look at your swing. As its been stated above, they usually can diagnose this right away. He also put me on video to confirm what he was seeing "live" and gave me some things to work on for more consistency. I can count on one hand how many slices Ive had since these two lessons, and I no further fear standing over the ball with my driver, in fact it has become one of my strong suits over the past season.

Good luck and let us know, what worked for you...

Hey Jacob,

I'm in the same boat as you and will be contacting a Pro soon.  For me it's been going on too long.  When i'm at the range, everything looks fine.  I get the course, what just happened??  It's been killing me score and It's been frustrating.  

Glad you posted this.   

Good luck and hopefully you can work it out soon!