The way I do it is keep all my males together and isolated, and keep all my females together far away.
When it is time to pollenate, I take a paint brush and a small envelope, and carefully harvest pollen from the chosen male. I then seal the paint brush inside the envelope and tke my selected female away from the other ladies and pollenate just a couple very low buds with the paintbrush. That branch gets a label giving the cross. You can do several crosses on the same plant this way. The female is allowed to rest a couple hours before being misted with plain water and then returned to the flower room.