Originally Posted by prathmann

There are two approaches. Some axles have a groove down their length and are designed so a washer with a small protrusion fits between the cone and the locknut. The protrusion sits in the groove and keeps the washer from turning and therefore the cone won't turn as you tighten the locknut (but it will still be pushed in a little so needs to be just a touch on the loose side before tightening the locknut).

Without the groove and corresponding washer you need to use a thin wrench (cone wrench) to hold the cone in position as you tighten the locknut against it.