When first imagining why you want the butterflies, think where you want to use them. Be it on the bedpost, on a lamp, on the side of a mirror or even to cover the frame of a family photo.
This is quite important, because if you can use different materials to make the butterflies, and it may depend on where you want to put them.

You can find a store with art supplies, or any other major store, or even with leftovers you find in your own home.
You will need some cardboard, some butterfly shapes, a crayon, scissors, some watercolors - whatever colors you like, 2 or 3 small brushes, needles, glue, some very thin wood sticks or metal wires (at your choosing) and a lot of imagination. And some patience.

You can find on the internet blueprints for butterflies, or, if you prefer you can draw them yourself. Use the crayon on a piece of cardboard - not too small, but not too big - and draw freely the butterfly. You can have it with 2 or 4 distinctive wings. Cut this piece out with the scissors. This is your first blueprint for the butterfly.
If you want different shapes - repeat the process by drawing something else. Cut it out and now you can have as many blueprints as you like.
If you do not have cardboard, or you want to use something else - you can. There are metallic soda cans or jar lids or thin colored plastic.

Once you have the blueprint, use it on the bigger piece of cardboard. Draw around it, make sure your drawing is clean, and move on. You can have 15, 20 or as many butterflies as you like.
Cut them out with the scissors and prepare for the next step.

With your watercolors, you can draw each butterfly as you like. Use red and black and yellow, or green and brown, or pink and grey, or whatever combination you like. You can use even black and white.
After you finished painting on one side, let it dry, and move to another butterfly. When you finish the last one, presuming there are a few, you can return to your first painted butterfly and color it on the other side too.
With a little patience and being careful, you can have at least 30 butterflies in one hour.

Varnish, or lacquer, is a product used to give shine and durability to different types of paper. It is mostly used in paper crafting, and you will find them in art supply stores or crafting supply stores.
After all the butterflies have dried, you can use one clean brush to apply the varnish on the butterflies. Proceed as you did while painting colors - first one side, and after all is dry, you can apply it on the other side. If you feel that once is not enough, you can apply a second lair of varnish.

So, after all is dry, now you have a swarm of nicely colored butterflies.
If you want to use them on the side of a mirror or a frame - bend the butterfly in 2 on the middle, use some glue, and simply glue it to the desired spot. Make sure it sticks there. You can use as many butterflies as you like, as long as it is not too crowded.
If you choose to put them on a lamp, you can use the needles - or pins.
If you want to put them in the flower pots - you can use the metal wires, or the thin wood sticks. You can adjust the wires and you can make an arrangement that can look like the butterflies are already flying - that is if you put them a little higher than the flowers.

Everything is limited by your imagination!