I'm going to tell you one thing. If you don't listen to anything else I ever say, just remember this one thing and do try to implement it.

Surprises are bad.

Surprises are those things that force others to react to a situation with minimal preparation. Surprises that are meant to take place in front of a crowd of people are even more dangerous.
Proposing marriage in front of a crowd, presenting an elaborate or expensive gift to show off to others, setting up someone for a surprise party by helping them think that they've actually been forgotten are all examples of surprises that are selfish surprises.

I suspect that there are good surprises too, but to me those would be like telling your sweetie that you've got the funds and the information to plan a cruise for six months from now and then settling down to play the trip together. A good surprise would be telling your friend that you are going out to a new diner before you leave the house.

A good surprise takes into account the comfort and wellness of others. If you show up on my doorstep with a brand new dishwasher and the six man crew to demo my kitchen and rebuild the sink and counters around that dishwasher, I'm going to wish I was dead. I will not be happy, I will cry. Because there is no way in this world that I would feel okay letting a stranger demo my cabinets before I had a chance to scrub them underside and back with bleach.

If you really want to treat someone to good news or a gift or a celebration talk with the people who are closest to that person and get their feedback on the matter. If part of your surprise takes place during a party or event that someone else is running, check in with the host to make sure that you're not making any more work for that person. If your plan could add work or take away fun or comfort for anyone else, work out a different plan.

We used to have "surprise inspections" when I was in the service. How these would happen is like this: The Battalion Commander would put the inspections in his schedule. His assistant would let the Company Commander's assistant know when they would be by. The Company Commander's assistant would let the Platoon Sergeants know and the Sergeants would whisper into our ears. End result, everyone looks good, everyone is happy, healthy communication has made for a win win situation with lots of good esprit de corps and all positive things are reinforced.

Please consider this alternative style of surprise for all of your witty social needs. Try seeing it as less of a chance to "get" someone and more of a chance to let someone else shine.

The public humiliation you avoid may just be your own.