All depends what your after. Most look for the most vigorous. But there are more factors to take into account. If your looking for color than you look for the most vigorous male with color. Some like color leaves others look for colored buds if your male has colored sacs than it can be past on to the buds in off spring. Some males can produce heavy trichome coverage those are great to breed with but it also is strain dependent and won't be something that shows up in abundance unless your using genetics that is known to get frosty. You can also look at speed of growth and speed in which they show sex. i wouldn't suggest smoking a male I've tried it twice and just ended up with a headache, iMo smoking the male won't tell you the potency, may be different for others but doesn't work for me. I'm have a theory and will be testing 2 factors when it comes to male potency once I do more tests I'll create a thread. Good luck hope that helps