1. Armpit Hair. This is the #1 issue. All too often, I see guys with abnormally long armpit hair trying to pull off the sleeveless shirt.... like hair so long that I could french braid it. Now, I don't suggest you shave your armpits, but honestly-- there is nothing more frightening than when a guy puts his arm around you, and you get a face full of long, mangled armpit hair that is clotted with deodorant chunks. Tip: Trim with a scissors so it's not more than 2" long.
2. What's on the shirt?
Anything related to beer, sex, politics, or rednecks is
3. Strap Width.
There is a huge difference between a spaghetti-strap and a capped-sleeve. We want NEITHER. Find a happy medium. Rule of thumb: The strap should be at LEAST 3 fingers wide.
4. Wifebeaters.
How could something called a "wifebeater" look anything BUT trashy!?? Not even Eminem could pull it off. Unless you're under the hood of a car, there is simply no excuse to sport such a derogatory garment alone.
5. Do you lift weights?
Whether your biceps resemble balloons or toothpicks-- it doesn't matter. It's about confidence: shoulders back, chest out, chin up.
6. Farmer tan.
Don't feel obligated to get rid of a farmer's tan-- some girls find them sexy. They suggest that you are probably hardworking, determined, and active.
7. DIY (when done right) = HOT. Oftentimes it's hotter to see a guy in a sleeveless shirt that he made himself (by cutting the sleeves off) than a guy in a manufactured, store-bought one. You seem more capable and resourceful if you make it yourself... there's nothing hotter than a handyman.
8. What The Flannel?
There is really never an excuse to wear a sleeveless flannel shirt-- unless you're going for the "hot, sweaty lumberjack" look.
9. Bottoms Up. This rule is simple. If it is cool enough to wear pants, then you really SHOULDN'T be wearing a sleeveless shirt. Sleeveless shirts are good for hot weather, but in cooler weather, they carry a different connotation-- starting with "T" and ending with "RASHY."
10. Ulterior motives.
Here's a secret: women know when you're trying to show off your arms. It's 100% obvious. We notice when you're trying to flex your triceps while stretching in class. We notice when you cross your arms to make your biceps look bigger. Most importantly: We can tell when you only do arm workouts... it shows on your legs. So if you're wearing a sleeveless shirt just to show off the guns-- we probably have figured that out.