Animal products can not be composted. The only exception is egg shells.
All fruits and vegetables can be composted.
Coffee grounds and paper filters can be composted. If you use a Keurig you can get k-cups that can be composted. Some coffee brands with these cups include San Francisco Bay, Cameron's, Tayst, and Faro.
Tea leaves can also be composted and so can the bags if they are paper. You can further reduce your waste by using loose leaf tea instead of teabags.
Plant trimmings can be put in your compost as long as they are not insect ridden or diseased. If you don't like the look of grass clippings on your lawn you can put them in your compost.
Wood ashes can be mixed in your compost. Do not put charcoal ashes in your compost because it often contains chemicals that can be toxic to soil and plants.