Cut Your Petals
The first step is making your largest petals. Our large petals size was determined by the size of our 8 ½ x 11 paper size. We made the largest outer petals we could using the whole sheet of paper. Cut out 5-6 petals of that largest size. You can make one petal template of each size and cut the rest to match it.
Next make a slightly smaller petal size, and again make 5-6 matching flower petals of that size.
You're going to do this whole process for about 5 different sizes of petals, with some large petal sizes, medium petals, and smaller petals, making each one slightly smaller, and making 5-6 petals of each size, that will all be used to make one of the giant flowers. In the end you will have about 5 x 6 = 30 cut petals in total for one flower.
Each petal should have a small slit cut in the centre of the bottom of the petals, this will allow us to add dimension to the petals when we glue them.
Also cut out one large circle in the same paper, to use as the circle base of the flower to glue to.

Glue Each Petal To Create Dimension
Now give each individual paper flower petal some dimension. Add a little hot glue to right beside the slit in the bottom edge of the petal, and then glue the other side, overlapped on top of it. Do this for each petal.

Gluing Your Flower Together
Start creating the flower by hot gluing the largest set of petals to the outside of the circle base. Add a line of hot glue to the base of the petal and then add them to the circle base. Space them as evenly as possible all around the circle. Then glue the set of the next size down of petals to the base in a circle just inside the largest petal set. Do this all the way down to the second smallest petals. Depending on the center of your flower that you want to create, you may want to save the small petals for that.

Creating The Center of the Flower
The simplest option for the flower center is to create some petals that look like they're just opening up. To do this take your smallest petals and cut the slit in the bottom of the petal a little deeper than the rest. This allows you to fold the paper really tightly together. When you put a few of these glued in an overlapping pattern in the center of your flower it will look like a beautiful rose center.
You can also make something that looks more like a stamen in the centre. Use a rectangle of paper and cut long slits almost to the bottom all the way along, and then roll up the paper. You can use a pencil to curl the fringe and then glue this piece into the center of your paper flower. Try changing the width of the fringe for a different look, or the length of the fringe pieces, or the direction it's curled in.

As a final touch to the giant flowers, you may want to curl some of the edges of the petals, either inward or outward. You can use a pencil, or the handle of a wooden spoon to help with this step. Take care not to crease the paper as you work.