Having 2 spots to grow in are best. Flip plants to 12/12 after 3-4 weeks veg. When the male starts to show sex isolate him. Collect pollen from the male when he's starting to open the majority of his pollen sacks. This can be done by shaking the plant onto a mirror, and scraping off the pollen into a container. Separate the male flower petals that will also fall off, from the pollen.  Keep pollen cool and dry.  A small envelope works good for storing pollen .  When your girl starts to flower, apply pollen to the girls pistils. A small artist paint brush works well to dust the girl with pollen. This is usually done 3-4 times, during a 2-3 week period ! More dusting equals more seeds. Seeds mature 5-6 weeks later.  GL