How to Lose a Potential TM in 10 Ways

Fail to use it, and someone else starts to use it first.
Fail to research it, and get a cease-and-desist letter from a person with first use.
Fail to use your trademark exactly as you applied for it (spelling and spacing count)
Fail to file an extension to prove use
Fail to file your Sect 8 affirmation of continued use (a/k/a 5^th year filing)
Use a term that is very similar to a Trademark you already know is used on a similar product
Use a Generic Term or only Terms that describe your product
Include terms that describe Geographical Locations
Use a common Last Name or a Biblical reference as your mark
Include a photo of someone without their permission.