The top ones for me that my pet could surprise me with would be:
During the day take NSFW pictures of yourself and remind master you're at home missing their touch and discipline.
Coming home from a long hard days work and walking in the door to find my pet sitting on its knees waiting to suck my cock and relive the day's stress.
Inviting a friend over for master to use together with you is an amazing surprise especially if you've seen master admiring the friend