Personally I find that it's easiest if you first put a deli cup over her and get her out of the enclosure with that, and then let her walk out of the cup and onto your hand. I've found many tarantulas to be far more skitting in their own enclosures then once they're out.
Aside from that, it's really just something you have to learn with practice. Eventually if you keep at it, you'll get over your fears. It's natural to be nervous the first few times, you just have to know where to draw the line - if you're so nervous that your hands are shaking and such, then perhaps you just shouldn't handle her because you may startle her or get startled yourself and drop her, etc. Tarantulas don't benefit from being handled, so it isn't the end of the world for the tarantula if you don't handle them. It's not at all necessary to handle a tarantula - I'm only comfortable handling three out of my twelve, and even then I hardly handle them unless it's for a demonstration.