Just my two cents, but I find taking cuttings when you can get them off of the lateral branches and keeping them until the flowering is done and smoked to see if there might be a keeper in the bunch. This method might be a bit time consuming for some but it allows you time to figure out the males, you might have a keeper male, if making seeds is a goal. This also ensures that you have a clone of each female, you might have a plant which shows off very late in flower, shorter flowertime if that is an issue or just be more the high you are looking for. I realize all of this depends on space, your time devoted to this and such.
I understand in today's world many are rushing everything quicker flowertimes, faster growth of the plant and life in general, the plant though is still set by genetics it will show sex at between 4 and 6 weeks all by itself. The males will normally show first and makes selection of your cuttings easy if you are only concerned with keeping a female. The most important factor is labeling your plants so that you don't get them mixed up and toss the wrong clones. A bong or pipe full without labeled plants is a sure way to make the mistakes, I know I have over the years.
Good Luck