[Karen Hart]

This is an interesting topic. There are several ways to go about it as have already been mentioned. 

Modification of your male name. This is good because if someone calls you from behind, you are more likely to "hear" it.
Also, it makes it easier for friends to remember it.

Keeping your same initials can be an obvious benefit. 

One thing that I would add is to let your spouse give you your name. It honors them and they are more likely to relate to it.
If you were to choose a name that they could not relate to, that did not fit their vision of you, they may feel very awkward calling you by that name.
However, this never worked for me!

Over my many years of dating, I had plenty of girlfriends who had no problem with my crossdressing but none of them would ever call me by any feminine name,
neither when I was dressed, nor even when we were being intimate. I really longed for that.
When we went shopping, they would say things like, "Do you think your sister would like this dress?" meaning "me".

I chose "Karen" because I always loved the name and it felt soft and comfy... and Hart because, well, you get that, right?
This was way before "Karen" meant -- somebody you would hope to avoid.

Karen