Find a solvent what dissolves your compound while it's hot and not if it's cold. How? Do experiments on a small scale, e.g.: in a test tube.
In many cases if you try to grow crystals from what you find home, water or alcohol will work as a solvent, or the mixture of these two. Remember, always try to find a solvent or a combination of solvents what only dissolves your material completely when it it hot.
Add some of your previously powdered substance to the right solvent and heat it up, until it is dissolved completely.
If if doesn't dissolves your material completely, than add a bit more solvent, or heat it until it boils, or if it still wouldn't want to dissolve it, filter our the insoluble material.
When it's ready place it at a place where it could cool down SLOWLY! Golden rule of crystal growth is: put it on the shelf and forget about it.
If you do every step correctly, than it should look like this:
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