Green Sparkles (I used two colours; a light green and a darker one and mixed them)
Small bottles, preferably with corks (available at a dollar store. I found a pack of about 10 tiny corked bottles containing beads. I simply emptied the beads into bags and used the bottles. It cost about $1.50)
You could also dye sugar green should you want to make your Floo Powder edible or do not have any green sparkles available
I've also found a recipe at planetpals.com to make salt sparkle like glitter. It might not taste as good, but if you'd like to try it, here's the recipe:
1/4 cup of salt
1/2 teaspoon LIQUID food colouring
Mix the salt and food colouring in a small bowl until the salt is uniformly coloured. Spread the mixture out in an even layer on a foil-lined baking sheet. Bake in the oven for 10 minutes at 350 degrees Fahrenheit. Allow your homemade glitter to cool before using it. Can be stored in an airtight container for several months.
Quite simply, mix together your sparkles (if applicable) or dye your sugar green, and put it into the bottles. Print off the picture provided below and resize it to fit your bottles, then glue it on. And voilà! A cute little bottle of Floo Powder to give to your guests!