Paint your item, give it a few good coats and let it dry.
Spread your glitter out on a flat surface. A cookie sheet with wax paper works great for larger items. A paper plate or sheet of paper works for smaller objects.. Make sure your glitter color matches your paint color. Green paint= green glitter. Pink Paint= pink glitter.
Dip the wet paint side down into the glitter and move it around so that every part gets covered.
Pour your glitter back into the container. A little glitter goes a long way.
Let it dry for 20 minutes or so and spray with a glossy acrylic sealer.
If you feel like the glitter is still flaking off after one coat of spray, a second coat can be applied.