This is a to be continued section for right now..so bare with me.
I made the facehuggers and eggs out of cardboard and recycled cardboard. I added texture using Great stuff crack foam and also paper mache clay (paste, joint compound and toilet paper).
To start the alien eggs...
1. you need two circles for a top and base. This is depending on the size that you will want. If you want small eggs, you can use a balloon, but if you want them movie quality (which is between 2 1/2 to 3 feet) you will have to build a structure yourself. Yep, that's right, no taking the easy way out this time.
2. You will then need some thick strips of cardboard. You are going to attach the cardboard strips to form a box shape to the circles. They will resemble a dumbell kind of shape. (Above) It doesn't really matter how big the box is its to support the egg. Paper Mache can tend to be really heavy when multiple layers are added.
Above is a photo of the egg frame that is posed hatched. You out petal shaped cardboard pieces and attach to the top of the egg using masking tape and hot glue.
You can paint the egg whatever color you wish, I chose to paint the texture detail a dark chocolate brown and the great foam is painted black then the egg is painted a dark gray, that has been muddied with the brown. The top of the egg gets a black circle to show that the egg is hatched and then the petals are painted a flesh color. It is really your choice on how to paint it. Watch the movies to get inspiration. Once the egg is painted and dried completely, I then brush on a coat of Spar Urethane. This will waterproof the egg, just make sure to get it into all the nooks and crannies.