Although we are 5 yrs down the line I agree with Stanwal. ;^)
The Graham is the easiest method I've ever used and the most easily re-checked (i.e. by putting it back on the jig any change in position due to applying the stylus guard or loosening of cartridge screws is immediately apparent - as I discovered recently!)
The only advice I would give is to be careful with self-induced parallax errors.
The Graham method is very comfortable and easy on the eyeballs with minimal risk of damaging the cart during install.
On the subject of parallax errors I would also suggest that using a 400X or 800X magnifier on a cart is not as straightforward as the casual purchaser might think. Ideally, the cart would be attached to a machined platten with the microscope locked on to it and with the capability of adjusting it to an exact measuring position. Since you really want the stylus to be standing upright on the LP at the time of measurement such accuracy isn't even remotely possible without a variety of angular errors occurring. Eyeballing cartridge vs microscope orthogonality isn't a reference point I would personally rely on.
Just my opinion...
The Graham is the easiest method I've ever used and the most easily re-checked (i.e. by putting it back on the jig any change in position due to applying the stylus guard or loosening of cartridge screws is immediately apparent - as I discovered recently!)
The only advice I would give is to be careful with self-induced parallax errors.
The Graham method is very comfortable and easy on the eyeballs with minimal risk of damaging the cart during install.
On the subject of parallax errors I would also suggest that using a 400X or 800X magnifier on a cart is not as straightforward as the casual purchaser might think. Ideally, the cart would be attached to a machined platten with the microscope locked on to it and with the capability of adjusting it to an exact measuring position. Since you really want the stylus to be standing upright on the LP at the time of measurement such accuracy isn't even remotely possible without a variety of angular errors occurring. Eyeballing cartridge vs microscope orthogonality isn't a reference point I would personally rely on.
Just my opinion...