Thick and Goopy?
Do not throw it away!! Polish never goes bad; just add some nail polish thinner to it. Nail polish is a great lifetime investment, and art. Also I know many nail salons add remover to their polishes to keep them thin, but do not do this it WILL ruin them!
Thin and Watery?
If you need to thicken a polish up, just leave the lid off of it for 10-15 minutes, check it, and repeat if needed, until you get the desired consistency.
Removing GIitter Polish taking forever?
Use the Foil Method. Soak 10 cotton balls/pads in 100% pure acetone, and place them onto your nails, making sure to cover the entire nail. Then cut strips of foil, and wrap your cotton covered nail in foil. The foil prevents the acetone from evaporating. Wait about 6-8 minutes, and while applying a little pressure on your nail, drag the pad and foil off. No more scrubbing like crazy.