Offensive Gamertag
Stay away from offensive gamertags. Don't use swear words or offensive language. Xbox Live will not accept any gamertags with inappropriate language. Those that do make it through approval can still be deemed offensive by other players. Avoid any tag that includes racist, sexist or homophobic language.
Your Name and Age
Avoid putting any personal information in your gamertag. While you may need to add numbers to your gamertag if someone already uses it, adding the year you were born will immediately tell other gamers your age. Instead use a random sequence of numbers or the year you got your Xbox 360. Additionally, don't include your last name in your gamertag. If your name is John Smith and you were born in 1992, make your gamertag ̶0;JohnS2010̶1; and not ̶0;JohnSmith92.̶1;
Gaming Interests
Pick a gamertag that reflects your gaming interests. If you are a fan of first person shooters, you might select the gamertag ̶0;FPSdude̶1; or FPS4Life.̶1; This tag will allow other players to know right away to invite you to play a certain genre.
Hobbies
Use a gamertag that is based off of your other interests. You might love films so your gamertag can be ̶0;FilmGirl̶1; or ̶0;MovieBuffed.̶1; This tag will add a social aspect to your gaming, allowing other players to quiz you on recent films or other interests.
Your Brand
Select a gamertag that is part of your personal brand. For example, if you run a blog named ̶0;Angry Gamer Kid̶1; then you may want to set your gamertag as ̶0;AngryGamerKid.̶1; This can act as free publicity for your blog.
Gender
Don't feel the need to include your gender in your gamertag if it makes you feel uncomfortable. Girls may get harassed by male players or vice versa. If you don't use voice chat and wish to remain anonymous about your gender, avoid words such as girl, dude, boy, guy, gal and so on.