well Northern Lights is a reasonably stable strain that is pretty much a good cloner, while as Big Bud is another story completely. So having the NL in the gene pool will help. Also build up carbohydrate levels in the momma plant by reverse foliar feeding (spraying with plain water for several days prior to taking clones). This will also help to decrease Nitrogen levels, which will also help in the cloning process. Clones taken from the bottom of the plant will root the easiest and quickest. Flushing your planting medium will also help prior to harvest. Good Luck