When it comes to throwing a successful surprise birthday party, the first key is coming up with a theme so that everyone will know how to dress or what to bring; this will be a lot more fun than if you were simply to have a surprise party that everyone “just attends,” as giving the party a theme will give everyone something to be excited about and something specific to do.
After you have figured out what you want the theme for the party to be, you will need to let everyone know about the party; nowadays, the best way to notify people of something such as a surprise party is to use e-mail or Facebook; as you let people know about the party, make sure it is prominently stated that the party is a surprise – otherwise, you could end up with someone who does not even realize that it is supposed to be a surprise, and who ends up letting the cat out of the bag.
And of course, you will need to have a plan in place on the night of the party itself so that the person for whom you are throwing the party is truly surprised; do what you can to figure out something that will keep the person from being suspicious, and you will be able to keep the party a surprise right up until the last minute!
The last thing you will need to make sure you keep in mind when you throw a surprise party is the fact that some people would not be especially keen on being surprised; before you go through all the work of setting up a surprise party, think hard about the person for whom you are throwing a party – and make sure that this surprise party will be as fun for them as it is for you!