Choose your male plant with best attributes, i.e. vigor, maturity, pest and mold resistance, and with your favorable traits (short, dense branch, floral density...).
Once you have select who is to be dad, then remove the other males and destroy them, it's a hard thing to do, but you must make sure only your selected pollen is the one that pollinates.
Keep very thorough notes on all attributes of the father.
It's worth noting that dry pollen can be stored in the refrigerator at five degrees Celsius in an air tight container like a film canister; make sure the pollen doesn't get wet as this will kill it.
To collect pollen, you can actually cut the flowering male as soon as you see male buds form, and before they open into the five banana shaped stamen and lay it down in a bowl of water with a weight at the base so that the top is sticking out and the cut base is under water.
Then place some baking parchment under the plant and seal it up in an almost air tight box; you don't need a light in there, the plant will continue to flower and drop its pollen onto the parchment paper.
When removing the paper from the box you need to take great care not to allow the pollen to become air born and you can improve your chances by use of a room ionizer which will help keep the pollen on the paper.
Remove any flower parts from the pollen with tweezers as the flower parts can spoil the pollen and carefully filter the pollen grains through a mesh; I use a pipe screen fixed to the end of a rolled up sheet of metal cut from a beer can and held by parcel tape.
Once the pollen is filtered you need to allow it to dry for a day, then it can be placed directly into a film canister and the canister placed into the fridge but not the fridge door as the temperature varies in the door.
Again when choosing a mother, select the plant that has the best characteristics as you did with the father and make note of the attributes of this plant also.
When you're ready to pollinate the female plant then select a bud with white hairs and use a small artists paint brush to dab the pollen from the canister onto the hairs.
You only need a very tiny amount of pollen and the more white hairs you pollinate then the more seeds you get; tie a plant label to the branch you just pollinated and write on the label the father and the date.
Pollinating only one branch is good because the rest of the plant continues to flower so you don't waste a plant; this has the added advantage for you being able to sample the plant in order to add the effects and taste to your database of attributes to the female plants record.
Allow time for the seeds to fully develop and don't be temped to harvest the seeds on that branch too soon; undeveloped seeds don't germinate well and are more prone to disease and early failure.
When you can see the dark seed poking out of the calyx then you know it's ready so you can take that seed; this is usually about two to four weeks, sometimes more depending on the genetic makeup so inspect on a daily basis. Take note of the date of the first seed so you can add this information to the database also; you can never have too much data.
Ultimately you want all the seeds to be ready at about the same time; however in reality this is not always the case, so you are better off harvesting each seeds as and when it becomes ready.
One last thing, when handling pollen you should change your clothes, take a shower and wash your hair before entering into the flowering room, and when pollinating make sure your fans are off, and preferably isolate the female plant to another room where it will stay while you are pollinating so that it doesn't pollinate the rest of you plants.
Once you start making your own crosses you won't look back, trust me on this, and the very best luck to you.
BTW this method of collecting pollen was my own discovery from much trial and error, so I know it works well.