Get the glass bottle and fill it until there is about 1/4 left

After that add as much dye as you want

When you're done with that get a funnel or you could make it yourself out of paper, and put glitter into it

The last step is to just hot glue the cap on to the bottle. ( this optional if you want to decorate the bottle) Be sure to shake it hard so the food coloring can blend

This what I ended up with