The above is correct.
In veg I look for structure. In my experience males that grow bushy and tight have a good chance of carrying other recessive genetics; i usually discard any lanky minimally branching males in veg. In flower, there are many factors, and it is more based on what you are trying to achieve with the cross. There's the flower structure itself, the node stretch and amount of flower sites, smell, resin profile, color, all kinds of things. Different strokes for different folks. I emphasize flower structure, plant structure, and smell; but any males that are not resinous are compost. Better to go back to the ol' drawing board there.
For the most part i make my strains with the high in mind foremost, and then various factors that make plants good for indoor growers. Outdoor cultivation is beautiful, but it is not nearly as widespread as indoor, and in my experience cultivars that do really well inside due to structure and flowering time will slay outdoors as well.