As someone who's been making crowns for about five years I thought it's finally time for me to make a how to on it! With this instructable you can make a wire crown, a full flower crown, or a mix of both!
This is my first how to and I'm glad to share it with you :)

Step 1: Materials to Gather

For this instructable you'll need:
Hot Glue Gun + hot gluesticks (High heat intensity gluesticks recommended in case of high temperatures. Not required but as a precaution, as I learned from experience; flower crowns can melt in a hot car when not taken care of)
Thick & thin wire (for the thick wire I used around 12 gauge and for the thin I use any pliable wire)
A bit of foil
Semi-sphere marble
Black marker + color of your choice
Floral tape and scissors will be your best friends in this
Fake flowers of your choice (if you want a wire crown you won't need these)
(Gold nail polish is not required but definitely recommended)

Step 2: Eye See You

To make the eye take a small piece of foil large enough to cover the back, and color light then dark stripes. This will mimic the depth of an eye! Use black to create the pupil, you can make a horizontal or vertical line or even a little dot.
Trim the foil and apply glue on the back of the marble to avoid smuge on your drawing. If you want it plain, skip the drawing and just paste it to the foil.
Nail polish is optional but I used some gold to cover the corners and ensure it sticks.

Step 3: Base of the Crown

Using the thick wire, make a ring the size of your head, connect both ends by looping them to look like arms holding each other.
To create the center wire part, draw a design for the eye to the size of your choice. I drew only one half because both sides are symmetrical and I can just flip the wire.
Following the designs, bend the wire to the drawing and keep bending till they fit happily together.

Step 4: Bonding Like Good Friends

Using thin wire cut three or four inches off, loop twice, tighten, loop three or two times more, tighten, and trim the rest of the wire off. You should bond wherever two wires meet in order to keep them together so they don't lose their shape.

Step 5: Eye Found a Place in the Middle

To place the eye into the center (or plain marble, if you wanted) you will need to use thin wire again! Wrap two top corners, bring them to a twist in the center, and as you approach the bottom wrap the two wires to separate corners.
Hot glue that bad boy onto the twist and done! You can also apply that gold nail polish I mentioned earlier to cover up the twist.
If you just wanted the wire crown, you can stop reading here and have fun with it!

Step 6: Adding Flowers

Your flowers are important! And should be treated as such, variety and patterns in a flower crown make for good details and make it interesting to look at. If you feel like making just a flower crown go for it! Add a center flower if you want to make the wire crown double sided.
To apply the flower, simply pluck one from its bouquet and snip the receptacle that connects the flower to the stem into two. This will act as a mini clamp to the wire; use hot glue, quickly pinch it together, and apply more glue to stabilize the sides.

Step 7: Patience and Repetition

Keep adding flowers until the crown is full, you can do this to plain wire to make a crown without the tiara looking part for just a simple flower crown!
I also added leaves and even binded two of them with wire in the front, you can also do this too if you want some foliage to go with your flowers.
Use floral tape (I recommend the wrap tape kind to the sticky tape kind to avoid the tape catching onto hair) to loop around the flowers. While wrapping be sure to pinch down and roll it tightly to keep it together, going over the wire and flower twice in different directions helps to also stabilize the flower's positioning and glue. Don't be afraid to work in small pieces of tape! If you're afraid of the tape coming apart add a bit of nail polish or hot glue to keep the end down, I normally skip this because if you pinch correctly the tape doesn't come back up.