To make an origami paper egg, you'll need a square sheet of paper.  Here's how to get a square from a standard sheet of paper.

1) Diagonal Folds: Fold the paper in half diagonally so opposite corners meet evenly. Repeat with the other corners so your folds look like the photo on the left.

2) Sideways Fold: Flip the paper over and then fold it in half so the sides meet evenly.

3) Triangle Fold: Pull the endpoints of the sideways fold together.

The paper will flatten into an isosceles triangle.

Flatten the triangle

4) Diamond fold: Fold each end point to meet the tip of the top of the triangle.

You can customize your paper egg, (or paper ball or balloon) a bit in step 4. Each pair of flaps can meet in the middle, or each side can be folded alone.  Try making both to see how they turn out.

If you only folded two, flip it over and fold the other two up as well.

The next sequence of steps will be repeated from each of the four corners that you can fold like you're turning pages of a book.

5) Make The Pockets Fold: Fold each of the four corners in to the center.

6) Tuck in the pockets: Repeat this sequence with each of the four corners.

6a) Hold the step 5 fold down, and fold the loose flap above it snugly against the edge.

6b) Fold the pointy tip back in to the center.

6c) Lift the flap you just folded in half, pull out the flap beneath it, push it to open the pocket, and tuck the 6b flap into the pocket.

When you tuck the flaps in, the paper egg will look like this:

Now, hold it so the end with a hole is up and blow really hard into the hole to inflate the egg. It helps to gently pull the sides apart while you blow.

This origami bird nest project can be a paper balloon, paper ball, or a paper bird egg.  I put mine in a paper nest with a paper bird on top, and sometimes make them with a paper bird inside as a special treat to share.