#1 - MAKING THE CLUB ANTI-SLICE
I have given lots of lessons where the player has turned up with clubs that are super upright - 4 degrees is not uncommon - and drivers that have the weights in the heel of the club to help stop or reduce their slice.
This does a couple of things. It reduces the chances of aligning the sweet spot and with more loft on the short irons it actually makes the ball pull/hook more than a 5- or 4-iron, for example.
The problem I have as an instructor is that if I fix a slicer's dramatically out-to-in swing path, making it more neutral, then we can have an issue where the player starts hooking the ball because of the setup of their clubs - less so with the driver because of their adjustable heads.
I then have to recommend changing the lie angles, which can then mean the player thinks he or she has not had their swing fixed or that they've been sold the wrong clubs.