Given how tsundere and stubborn Cloche can be, it's often easier to take her by surprise and force rather than taking the time to earn her trust, but also remember that her sword isn't just for decoration. The big upside to earning her trust is being able to tie her up in her various outfits, like the other Reyvateils, but her regular outfit is also wonderful as well. No matter what she's wearing, her inner thighs remain her weak spot and they are exposed in almost everything she wears. Other than that, utilize a gag that emphasizes her hair. If she shows you her dere side, you'll have reached a milestone.