You need the right location i.e. no chance of the phone ringing or other interruptions. Sensual background music and arromatic candles are nice to get in the mood and the room temperature should be neither too hot or cold. The bed or table your parner will lie on must be comfortable as well.
Start with a relaxing bath where you soap and wash her gently, then dry her with a warm towel, dress her in a bath robe and lead her to the 'massage room'.
L slowly remove the robe and lay her down and start by massaging her feet, hands and arms and legs. Your aim is to slowly work your way to her vagina where the real massage begins but don't rush it as it's all about relaxation and preparing her for the delights to come. As you have researched Yoni I don't need to spell out how to slowly bring her to orgasm so I'll only stress that slowly does it.
By the end of the session you will have built up her trust in you and she should feel safe in your hands. Good luck and do let the thread know how you got on!