Well, I hope you had a fun packed day. She must be bursting with excitement for the evening ahead.
Start tonight as you did last, with a bath including plenty of teasing. Get each other nice and clean, everywhere. Clean her arsehole with your finger, to give her a hint of what is to come. Tonight, you will take a little more control, but she will not know what is you, and what is instructed through this tease.
Once you have finished your bath, ask her to get into your choice of lingerie, or even better, if you took her shopping, whatever your bought together! Again, tell her to meet you in the bedroom.