Coning question

Is it best to cut them in the Veg or Flowering period, or does that matter?

in the veg if you mark the plant you cut it from that way when you stick that plant into flowering it will let you know weather or not you clone is female. putting a plant into flowering then back into veg can be stressful and possibly turn it into a herm!!

You want to do it at least 5 weeks into vegatating. The plant will be sexually mature but won't have to go through any undo stress during flowering. That way you can put the clone straight into flowering.