I reveg repeatedly. Sometimes, if you wait too long, the plant dies anyway. If you harvest during peak time, leave the bottom 4-6 branches with some popcorn buds and as many leaves as possible. Put it back to 24/0 light, and transplant it. (If you're growing in soil) CAREFULLY cut off the outer roots till there's about half the rootball left. Fill the pot so that when the plant is put back in, some of the originally above ground stem is buried in the soil. Before you put the plant in, dust the top of the soil with root tone or some other cloning powder. Fill the pot the rest of the way and start right into the veg nutes. In about 10-14 days, you'll either have a dead plant, or a plant with some really gnarly looking leaves and branches growing out of the popcorn buds you left behind. Most of the time, I get some nice growth, but sometimes, they die. I noticed some strains are hardier than others, so hopefully you can reveg your successfully. It is good practice to wait a day after harvest, so the plant can recover a bit from the initial raping.
This is just how I do it. Some have other methods. Look into it and be prepared before you start, and remember.....start with EVERYTHING being the same temperature. It's a common thing to overlook.
