punishment ideas...

You could add extra time to some of the existing ones or more strokes.

Sub is not allowed to speak a specific word of Mistress's choice for x hours (you can have fun with this one as your Mistress can try to put you in a position where you have to say it :) )

Cum restriction for x days

Sub must do all household tasks naked for the whole day

Public apology explaining what you did and why it was wrong posted to a public message board of Mistress's choosing