You can also take a few "practice shots." It sounds crass, but find some women whom you find interesting but aren't outright crushing on. Strangers are good for this. And just practice asking them out on dates.
You can also practice roleplaying with a close friend or your wife. The more times you say the words out loud, the less awkward it becomes.
“As I am sure any cat owner will be able to tell you,
someone else putting you in a box is entirely different
from getting into a box yourself.” —bisexualbaker