Trying to approach my mom...

Okay, so I've been working on identifyiong meself more as a male, and I think I'm ready to come out to my mom, but I can't help but feel worried/concerned on the outcome. She tends to be very difficult at times and we have had issues in the past (not concerning this subject) but I'm currently just trying to decide on how to tell her. She also has a very religious outlook in a sense, so that just adds to more concern and confusion. If anyone has any tips on how they came out to their parents, or on how to approach this, it would be really appreciated