Tank tops are only acceptable when working out. Period.
Open doors for women, and stand up when they arrive and leave the table.
Trim your nose hair/fingernails regularly.
Look and laugh at, but don't wear shirts that say- "Give me Head 'til I'm Dead" "Of Course I Love You, My Dick is Hard Isn't It?" and "GILF."
Tribal tattoos aren't cool or badass.
Don't go out to dinner if you can't afford to tip at least 20%.
Never show up for a party empty handed.
If your girlfriend/wife lets you watch football, let her watch something on Style or TLC.
Don't forget Anniversaries, birthdays, Valentines, etc. That's just asking for trouble.