So you want to try going commando? There's some stuff you need to know first.
Your dick will show more
It may seem blatantly obvious, but yes, your penis will show more when you're going commando. The removal of layers of fabric between your dick and pants means that more of an outline and more detail will show through the pants. If you're circumcised, the detail of your glans will definitely show more.
You can mitigate that with some of the same steps to reduce a bulge, namely by wearing darker colors and thicker fabrics, but the outline will still be much more prominent when commando. If you're long enough, that'll be hanging down a pant leg, which will only further emphasize the dick print.
When going commando you need to be comfortable with the fact that you may catch more glances, stares, and comments. A lot of people just can't help themselves.
Your dick and balls will be bigger
Unrestrained by any sort of underwear, you genitals will hang more. Simply by not being compressed, more blood will flow into your penis and scrotum, warming them up and extending them. This is further amplified by any additional heat, which will cause your balls to hang further away from your body to maintain an optimal operating temperature.
Hanging bigger will only exacerbate how much your dick print shows through your pants or shorts.
Short shorts = hanging out
You know how when you wear shorts and sit down, the legs ride up on your thighs? Well, when you're hanging freely the more of your thigh that's exposed the greater the chance your junk will slip out. With shorter shorts and longer penises you might even hang out when flaccid.
And if you happen to pop a boner? Good luck keeping that hidden when you don't have enough fabric to even cover your thighs. I'm not saying you shouldn't wear shorts with a short inseam if that's your style, just be careful that you're not dangling out for the world to see.
Prepare to sweat and stick
One of the benefits of underwear is that it keeps everything packed up neatly. Take that away and you not only lose the barrier between your dick and your pants, but also between your junk and the rest of your body.
If you're the type to get sweaty down below, it becomes a trade-off: better ventilation for increased skin contact. If you're particularly warm you may end up with cock and ball sack plastered against your inner thigh. If you're going to be very active, chafing is a real issue. Last thing you want is a rubbed-raw scrotum.
It might be worth considering pouch underwear as an alternative to freeballing.
Unrestrained, your junk will flop freely
This should go without saying, but without underwear to restrain your dick and balls, they will be free to move about inside your pants. If you're wearing loose pants, your junk flopping all about may be very visible.
If you're very large soft the head of your penis can end up under a leg when you sit, which isn't fun but isn't terrible. But it's not nearly as bad as the excruciating pain of a whole testicle getting caught under your thigh.
Speaking of testicles, being left to swing freely puts you are greater risk of testicular torsion. This occurs when a testicle turns around in the scrotum, twisting the spermatic cord and cutting off the blood flow. It's incredibly painful and requires rapid surgical intervention to save the testicle from damage and death.
There's also the matter of swinging freely leading to more stimulation and thus more frequent arousal. This is something that you can overcome by simply getting used to, but early on it's not uncommon for the increased stimulation of going without underwear leading to lots of unwelcome erections.
Still, maybe give it a shot?
All of that isn't to say far going commando is a bad thing. It can be incredibly freeing to not be encumbered by underwear all the time. The improved ventilation of fewer layers and restrictions can help keep you cooler. And for some larger guys struggling to find well-fitting underwear, freeballing may be their best choice for comfort without feeling crushed.