Use 10W dedicated fork oil.
Use good stuff.
Set by oil level and not volume added.
Suggest not using the stock oil level.
Instead, regardless of what springs you have, stock or aftermarket, use no more than 140 mm and no less than 125 mm.
For those spooked off by deciding what to use out of the above range.
If you feel your bike is really divey on the brakes, because you really use the front brake, go 125.
If you have stock springs and think things are OK as they are, go 140 and you'll avoid "clanging" when you find yourself giving your front brakes a fist full during a $ 1.10 moment.