Making this heart has a lot of steps but it is really easy. This is a cheap and easy way to make something special for someone you love on Valentine's Day or just because. You can put it in an origami box and give your heart away.

[edit] Steps

Get a square piece of paper.

If you draw a design, splitting it in half as shown, it will end up in the center of the heart. A decoration can be added when the heart is finished as well.
Turn the paper to the side that is white. Fold the top right corner downwards so that it meets the left side of the paper. Unfold it, do the same thing to the opposite corner,do not unfold .
Fold the bottom part that's still white in half, upwards, so that the white doesn't show anymore.
Unfold the top part so just the bottom part is folded. Then turn your paper over.
Fold the top part down across the center of the cross made by previous creases (along the green line shown; the top edge should meet the yellow line in the image). Then unfold it again.
Turn the paper over again. Take the left and right sides of the paper (where the horizontal crease is) and pull them toward you. As you pull them, the other two creases should be folding too. Pull the two sides inwards so they touch. This can take several tries if you are new to this.

If you look closely at the image (click to enlarge) you will see small blue and green crosses. The points marked on the left and right by the blue crosses will meet the lower blue cross, while the upper green crosses will meet the lower green crosses. This is essentially two reverse folds.
Fold the bottom left corner of the top triangle to the top and do the same with the opposite side.
Fold the left side towards the center and again do it to the other side.
Fold the entire thing in half vertically, then unfold. Turn over.
Take the two bottom corners and fold them upwards so they meet at the center.
Notice at the top there are three individual flaps; two small ones and a big one. Fold the big one down.
Tuck the two corners you folded earlier into the space inside the big flap.
Fold the two remaining top flaps downwards at an angle.
Tuck the corners of those flaps into the space in the big flap too.

[edit] Video

[edit] Tips

Demo

Fold neatly to make it look better
Demo

If you are using construction paper, you don't need to flip to the white side.
Demo

Practice. If you are new to origami, this can be hard and you may not get it on the first try.
Draw the design after folding, not before.
Look at the images carefully before making the folds to reduce unnecessary creases in the paper

[edit] Warnings

Beware of papercuts!
Do not use small pieces of paper on your first try!-you might get frustrated!

[edit] Things You'll Need

A rectangular piece of paper.

[edit] Related wikiHows

[edit] Sources and Citations

Origami Heart Used With Permission. By Neekko of Deviantart.com
5min - How to Make an Origami Heart 5min is a Videopedia for instructional videos. Source of images in this article, shared with permission.