Flash powder is the universal composition for almost all pyrotechnic reports. Bottle rockets, thunderbombs, m-80's, shells, everything. If it is not enclosed in a container then a bright flash along with a lot of smoke will be produced as shown in the picture. If it is enclosed in a container, even the smallest amounts will produce a loud report and a violent explosion.
If you are going to use this to make fireworks please note that fireworks must be legal in your state, you might need some sort of license, and that you can use no more then 50 milligrams per firecracker ANYWHERE no exceptions. Any firework that contains more then 50 milligrams is illegal in every state.
Flash powder was originally used for producing light for cameras about 100 years ago. You have probably seen something to this extent where a photographer holds a wooden handle with a flat platform on top, says look at the birdy, and poof he ignites the flash powder.
There are many different formulas for flash powder, I will explain the simplest one with the easiest chemicals to get your hands on.
Step 1: Chemicals
400-600 mesh aluminum powder. The mesh refers to the size of the particles in the powder, it may also be referred to by its actual particle size in microns. For micron size the smaller the number the smaller the particle, for mesh size the higher the number the smaller the particle. A general rule of thumb - the smaller the particle the better. Can be bought on e-bay.
Potassium perchlorate - it is the oxidizer in the reaction. It is getting harder and harder to come by, the CPSC is trying to outlaw many different chemicals, and potassium perchlorate is high on their priority list. As of this writing it can still be bought on unitednuclear.com.
Step 2: Mix
Aluminum powder 30%
Potassium perchlorate 70%
Before you start measuring out the chemicals, it is good practice to neutralize your environment by spraying some anti-static spray around where you will be working. It can be made easily by mixing 1 part fabric softener to 9 parts water and putting it in a spray bottle.
Using the ratio, measure out how much aluminum powder you will use and put it in a plastic ziplock bag (spray the bag with anti-static also) Then measure out how much potassium perchlorate you will use and put it in the bag. Seal the bag and gently shake it around until the chemicals are evenly mixed.
Once the flash powder is mixed do not seal it in any form of container, this will lessen the risk of an accidental explosion.
Do not store the flash powder only make what you are going to use.
Step 3: Use
Insert a 10 in. long fuse into the pile. (Instructions for fuse here http://www.instructables.com/id/E9ZBOE35P9EPA8KZXX/ )
Light and stand back. When the fuse ignites the flash powder a bright flash and pfft sound will be given off.
A large cloud of smoke will also be produced.
I know its hypocritical for me to say this but: Please be satisfied with that and do not make fireworks.
I have the experience to do these things safely, no matter how dangerous I make it seem in videos or photos. I know exact burning rates of all the fuse I use, proper amount's of powder to use, and proper containers to use, etc. So please don't try to make fireworks unless you know what you are doing.