Note: This is an advanced model - not recommended for beginners, but I'll explain the steps as best as I can.
If you are an advanced folder, start with a bird base and skip to step 4. If not, just follow the logical progression of steps!
A few terms you will need to know (but I'll explain them again when you need them):
Mountain fold: A mountain fold creates a mountain. Fold the paper backwards on itself so that it creates a mountain.
Valley fold: A valley fold creates a valley. Fold the paper forwards so that it creates a valley.
Inside-reverse fold: This is difficult to describe without pictures. You can either follow along with the steps, or, if you are still confused, go here: inside-reverse fold
Squash Fold: Again, it'll be easiest to see an example with pictures or just follow along with the steps. If you still can't get it, go here: squash fold
If there is any step or part of a step that is unclear, or you follow the steps and yours just won't look like mine, drop me a comment an let me know. I'll clear it up as best as I can.
Step 1: Preliminary Base
If you don't know what a preliminary base is:
Turn your paper white side up. Mountain fold the top to the bottom and the left to the right. Valley fold on the diagonal. Fold together and flatten into a square.
If you don't know what mountain and valley folds are (you really don't have any business folding the orchid):
Fold the bottom of the page to the top. Unfold. Fold right side to left. Unfold.
Flip the paper so the colored side is up. Fold diagonally both ways. Unfold.
Pick up the paper and fold in half. Pull both sides down and toward each other. Press the back flap and the right flap together. Press the front flap and the left flap together. You should now have a flat square with three layers. This is the preliminary (or square) base.
Step 2: Side Folds
Step 3: Inside Reverse Fold the Creases in Step 2
If you don't know what a bird base is:
The title is pretty self-explanatory. You want to preform an inside-reverse fold along the folds you just created in step 2 - on both sides.
If you don't know what an inside-reverse fold is, please follow the pictures, watch the video, or google it. It's really hard to describe if you don't use the notes on the pictures. But basically, you're turning your valley folds into mountain folds by folding them backwards. (Yes, I know I've only confused you further. Please, just look at the pictures.)
You should now have a bird base.
Step 4: Squash It!
If you don't know what a squash fold is:
Basically, you're just lifting up the side of the paper and squashing it so that the point is now in the middle.
In one diagram that I found, this is referred to as "the lily base with the small points tucked to the inside." This helped me exactly none, but it might help you to know what it is supposed to look like.
Now fold a one layer on the from to the right. Turn the paper over and fold one layer to the left. The model should now fully enclose two full points on the right side. In other words, there should be two flaps on the left and six on the right.
Step 5: Valley Forge... Uh, I Mean, Fold
If you don't know what a valley fold is, remember this:
Valley folds create valleys.
Mountain folds create mountains.
Fold the top down so that it creates a valley.
Step 6: Open Sesame
Step 7: Squash It 2!
If you don't know what a squash fold is:
Basically, just lift the triangle and then squash the point so that it is now in the middle. I like to use a chopstick to make sure that I get the top of the triangle to squash, too.
Step 8: Petal Fold
If you don't know what a petal fold is:
Follow along with the pictures. Pick up the bottom edge of the triangle and make it the top edge. The sides should start to meet in the middle. Crease the right and left so that they meet in the middle. Fold the top triangle down.
Step 9: Tuck It!
Pull on either side of the triangle. Fold backwards (mountain, remember?) along the creases you already made. Fold the sides back under the triangle. Repeat on the other four triangles.
Step 10: Rabbit Ear
If you don't know what a rabbit ear is:
(you're going to need the pictures for this one) Crease along the pink lines. Unfold. Bring the sides together to create a triangle pointing away from the rest of the model. Fold to the right.
Step 11: Time for the Details
2. Fold the flap so that it lies flat on top of the diamond.
3. Valley fold the right flap on top of the left.
Repeat 1 and 2 on the right side.
Step 12: Squash It 3!
Lift up the right side of the squash. Squash fold on this side. Petal fold the flap. Valley fold the small point down. Valley fold over to the right.
Lift the left side. Squash fold. Petal fold the flap. Valley fold the small point down. Valley fold over to the left.
Step 13: STRETCH
Open the stretched fold outward and valley fold down.
Mountain fold the point twice and tuck inside.
Step 14: Collapse!
Turn over so the free points are at the top (pointing away from you).
Step 15: Valley Forge (oops, I Mean Fold) 2
Valley fold two flaps to the left on top and two flaps to the right on the back. (This is called a Minor Miracle fold)
Valley fold the side corners to the center line (see picture). Valley fold the point down (this is the point that has all the details).
Step 16: Inside Becomes Out
Valley fold the front and back layers of the left petal. Repeat on the right (valley fold on this side, too).
Step 17: Lower Petal Lift
Open up the slipper by pulling out the small flap that we tucked inside earlier by mountain folding on this petal.
Pinch the sides to give a box appearance.
Step 18: Spiraling
Mountain fold the base point in half. This should make the top petal fall forward.
Step 19: Rabbit Ear 2
Step 20: We're Finally Done, YAY!
For a stem, there are several different options. You can simply stick a chenille stem in the base of the flower. Or you can take a stiff piece of wire and wrap it with green paper and attach it to the flower. Or you can just leave a pile of flowers lying around. Pretty!