One way for a submisson or ground and pound specialist to get a fight to the gound comes from getting double underhooks and then performing a throw/takedown. Check out Julie Kedzie vs Tonya Evinger in an MMA fight. Tonya gets it to the ground and then finishes with the rear naked choke.
Here's an in depth instructional on how to use the double underhooks to get the throw/takedown.
Here's another woman's MMA fight where the double underhook technique is used to perfection to get the fight to the ground and then an armbar finish.
Shayne Basler vs Jennifer Tate