How to throw a 
surprise party

Throwing a surprise party seems like a simple task, but a grand celebration requires a little planning. Determine a few basic details: what kind of birthday party you want to throw and what the birthday boy would like. Once you've thought out the details of the party, keep it a secret, while providing guests with plenty of information. To get the birthday boy to come, offer his chaperone some ideas on how to bring the guest of honor to the surprise party without blabbing.

Choose a theme for the party. 
Think about what the birthday boy likes and use that as the main theme. If you're throwing a party for a child, the theme can be their favorite toy or fairy tale. For an older birthday child, choose a theme based on his or her hobbies or interests. For example, organize a party based on his favorite movie. In this case, you can instruct guests to dress up as characters from that movie.
Keep in mind that you also need to plan menus, decorations and entertainment related to the theme. So if you're throwing a Hawaiian party, try having it on the beach or set up tropical decorations. Serve tiki cocktails and wear leis (Hawaiian flower necklaces) on your guests.

Choose a venue for the party. 
It can be held almost anywhere. It should be large enough to accommodate all the guests. So if you want to throw a grand surprise party, you may want to rent a hall in a house of culture. However, if you're throwing a party with a dozen people, you can easily hold it at a nice restaurant.
For example, you can have the party at the partygoer's home, your home, a restaurant, a park, or any other place you think will be unexpected for that person.
If you will be renting a space, find out what kind of speakers are available, and check the food and decorating policies.

Pick a date and time.
 Sure, you can throw a surprise party on the birthday of the birthday person, but you can surprise them even more by organizing everything a day or two earlier. You'll need to pick a time and date that works for most guests, and make sure the birthday boy will be available, too.
Ask the birthday boy if he would like to go out with you at the time you plan to throw the party. If he says he has other plans, you'll have to reschedule.
Don't throw a surprise party after the person's actual birthday, or they'll think you forgot about their big day.

Decide what treats to serve. 
People expect to see food and drinks at the party. If you're throwing a party for children, you can serve standard birthday treats (like lemonade, cookies, and cupcakes). For an adult's birthday party, foods that are easy to prepare and eat are fine. If you don't want to take the time to prepare the food, consider ordering catering services or having the party at a restaurant.
Match the treats to the time of the party. For example, if you're throwing a surprise party right after work on a weekday, most guests will expect a full meal. On the other hand, you can serve drinks and hors d'oeuvres during the day on the weekend.

Make a guest list. 
Determine how many people you want to invite to the party, and think about the personal qualities of the guest of honor. If he's not very outgoing, he's likely to enjoy a small party with his closest friends and family. If he enjoys crowds and conversation, you may want to call a large group.
You may want to ask another person to help you plan and organize the surprise, especially if he is really enthusiastic about the party idea.

Invite guests. 
Once you've thought through your list, create an event page on social media to invite guests, or call and invite them to the party. Don't send out paper invitations so the partygoer won't find them and know about the surprise. Make it clear to your guests that the party will be a surprise.
Decide if you want to ask guests to bring gifts or help with food and drinks.