I typically look for the most robust male that flowers first since I want as short of a flowering time as possible. However, that trait won't necessarily pass on from the male. I won't use the first male to flower if it's a spindly runt and I also have other criteria I use for determining which male to use. I do a smell test, look at branching, the leaves, etc... Just overall plant structure and stuff.
I use the same methodology when deciding which female to pollinate.
But I've also done open pollination with several males and females without concern for what each plant brought to the table. I do that with landraces to preserve as much genetic diversity as I can. I'm saving stuff. It won't be long before native cannabis around the world will be contaminated with higher yielding commercial hybrids. Once these landraces are lost they're gone forever. Some of us are saving seeds.
https://phytokeys.pensoft.net/article/46700/element/5/31/
, check your direct message homey