northern light cloning question/reveg

I grew White widow and Northern lights and got my mother plants growing. The WW is easy to take clones from but the NL is so compact i'm not sure how to get it to become bushier. I just topped it in order to promote side growth. I would welcome any tips on how to prune it when there are no shoots coming off.
Also, due to plenty of NL clones and no WW available this round other than one clone from topping the plant, I was thinking about revegetating a few of my original NL plants. How do you do this if they are just about ready for harvest? do you have to trim all the bud off first, then revert to 18/6 or 24/0????

Leave the bottom buds on your plant, (popcorn buds) and leave as many fan leaves as you can. Put it in 24hr light and give it a good veg fertilizer. In 2 weeks you should see new growth from the top of the buds. At 4 weeks you should be able to take some cuttings. After I have enough new growth to keep the plant going, I cut off the off growth.

Good Luck!