At least with the varieties that I worked with, the pollen became available at full darkness, a half hour or more after sunset. Wearing a head lamp, so I could gather the anthers and pollen in a film bottle, using both hands, I would use the pollen right then, at its freshest. Time availability to do it, and temperature, are usually good then--- if there aren't hordes of mosquitos.
Brushes did not work well. For flowers on flexible branches, where I could turn the flowers upside down, I would pour in the anthers and pollen.
For stiff positions, where the flowers cannot be turned up without breaking them off, I would smear pollen up them on my index finger.
Fruits resulting from carefull, full hand-pollination are usually more symmetrical and far larger than fruits resulting from partial pollination by insects.
