Entrance
When designing your tree fort, you must decide how you and your friends are going to get into it. One way is by building a ladder. If your friends are not comfortable climbing a ladder, steps can make them feel safer getting into your tree fort. For a physical challenge, include a rope to climb up into your tree fort. It can also be used to swing from as you exit the tree fort.
Features
Before building your tree fort, decide what features you want to have. Choose how many windows you want for lookouts to see your friends, or to use to keep an eye on rival kids in the neighborhood. Some tree forts can have multiple floors, giving you more space to play. A canvas or wooden roof can help keep out rain. Don't forget about a trap door on the bottom of your tree fort to make it easy to get out of if you're escaping from enemy forces, and a small platform held with rope on all four corners could be used to haul up food and drinks provided from below.
Exterior Decorations
Decorate your tree fort to personalize it and make it your own. Invite your friends over to paint it with the help of an adult. Paint it one of your favorite colors, such as the color of your favorite sports team, or use camouflage paint to hide from the opposition. Decorate the exterior of the tree fort with items such as flags and pennants to identify it as yours. Include your name or a symbol for your group of friends that play in the tree fort.
Interior Decorations
Make your tree fort your own private club house by stocking it with decorative and functional items. Place a rug or pillows designed for outdoor furniture in the tree fort for you and your friends to sit on. A small table and chair set will allow you to play games or enjoy meals in your tree fort when you're not battling foes from below. A shelf can provide a spot to hold ammunition like snowballs in the winter, or water balloons in summer. Don't forget to decorate the tree fort with items such as pictures or photographs from some of your favorite hobbies and sports. To keep pictures from getting water damaged from rain, laminate them. Remember, this is your tree fort: match it to your personality.