Select a construction paper first. You can use any colour from red, pink and white to make the hearts. However, red would tend to suite the occasion more, as you would be preparing it for the valentine's day.
Fold the construction paper in a half. Do that in such a way that both of the halves are equal, and none is larger than the other. You can ensure that by drawing a straight line in the middle of the construction paper and then using that line as the axis, fold it once. This would help you in creating a more real shape of the heart, as you'll only have to draw once, with the other part being a replica of original drawing/cutting.
The next phase is to draw the heart, which would serve to be the base for cutting out the heart later in another step. There is no need of drawing the whole heart. Instead, the easier way is to draw a half heart on the edge of the folded side of the paper. The heart should be carefully drawn as the upcoming steps would involve cutting on the basis of this shape. You'll need to draw the half curve-shaped drawing, doing that in a smooth manner.
Cut out the heart using the scissors. Make sure you cut it in the right shape so that it resembles the drawn shape in the exact manner. Start with the bottom of the drawn heart, cutting smoothly without pulling the scissors away. Cut around the boundary of the heart in such a manner that the drawn heart's outline is cut out of the heart that you're carving out of the construction paper.
You can also decorate the heart-shaped figure by adding further enhancing the outlook using colours, glitter and other such accessories. Make the additions relevant to the selected theme for the event.