I used to dip two cans of copenhagen per day. quit a few times, then always went back 'just this weekend'. On a visit to the dentist, he swabbed my mouth and told me it was full of precancerous cells.
So, I had to quit cold turkey. no 'one last mega dip'
Bought some nicorette though it just made me want to dip more.
One thing that helped me quit in the past was moving to a new place. I know it's extreme, but in a new environment i had could fight the urge much...