Going by initials is essentially gendered male, and the assumption is probably that you're male if a reader of your name had only your initials to go by. However, it can be convenient in helping people make the switch to a new name, and you can switch to your initials at any time without doing any legal change. This is another common decision. Dennis becomes Denise, etc. However, because this is fairly common, a lot of people might think your boy name must have been Dennis if you choose the name Denise.
Names go in and out of fashion.
The rankings of this decade's popular baby names are not applicable for when you were born. The advantage is, you can see the names that were popular during the time and place you grew up. In my case, Tiffany might have been a great name, but no one was naming their child that when I was born. The phone book can be a good place to choose a name. It's also a good idea to check if there's anyone else listed by the name you're considering.