With the ellipse still selected, go to Edit > Copy and then Edit > Paste in Front. This creates a duplicate of the ellipse in front of the previous one. Now while holding down Shift + Alt grab a corner handle and drag inward.
Select both ellipses and then go to the Pathfinder window. If you don't see it, go to Window > Pathfinder. While holding down the Alt key, click on the "Subtract from shape area" option. This will cut a hole into the ellipse.
With the ellipse selected, go to Effect > Distort & Transform > Roughen. The Relative size may vary based on the size of your object, but if you have the "Preview" option checked you can play around with the settings and see them in action. I used a Relative size of 7%, a Detail of 100%, and Smooth points. This is my result:
Now let's make copy of what we have, paste it in front and then size inward. Select your object and go to Edit > Copy and then Edit > Paste in Front. While holding down Shift + Alt grab one of the corner handles and drag inward. I changed the color of this object to a lighter green for both the fill and stroke and also rotated it a little bit.
We're going to repeat step 5 again. Select your newly created object and go to Edit > Copy and then Edit > Paste in Front. While holding down Shift + Alt grab one of the corner handles and drag inward. I changed the color of this object back to a darker green for the fill and white for the stroke. I also rotated it a little bit.
All that's left to do is add some decorations! Illustrator has some pre-made symbols, one of them being a bow. If you don't see your Symbols window go to Window > Symbols. Then click on the little arrow on the Symbols window and choose "Open Symbol Library" and then select Celebration.
Drag the bow from the symbol window into your document. Size it up or down and place to your liking.
Add any other decorations you like! Here's my final result:
