Aside from cleaning and re greasing cones, at 1000 mile intervals, another equally important thing, is correct adjustment. With quick release hubs, leaving a little play in the cones, allows for the tightening effect of the QR skewer. Placing two spacers over the ends of the axle (In place of the fork ends) and inserting the QR skewer, allows you to feel how tight the cones will be once in the bike.

In addition to using the correct cone spanners, it will be much easier to achieve correct adjustment of the cones, if you use an axle vice.