I have been working on this list of painting ideas for the last half year. Here is my start. 

Try painting:
WITH
Water color
Water color then cover with plastic wrap, let dry and remove plastic
Do a dot (bingo dabber)
Do a dot on dark paper
Frozen paint
Pudding
Kool aid
finger paint
tempra paint

Watercolor on ice block

How about painting on:
ON
Newspaper
Cardboard
Boxes
Laminating
Tubes
Crumpled paper
Ice
Tin foil
Wax paper
Paper towel
Felt
Big branch
Mirror
Rocks
Shells

You might try:
USING
Pine Cone
Pine needle
Flower
Weed
Yarn
Balloon
Ball
Bumpy ball
Cotton ball
Marble roll

Tea bag painting

Lego
Dinosaur
Animal
Brush
Foam brush
Roller
Sponge
Squeeze bottle
Eye dropper
Kitchen gadget
Fork
Scrub brush
Fly swatter
Spray bottle
Spaghetti
Rocks
Cups
Tubes
Bow
Comb
Bubble wrap
Car
Truck
Train
Cardboard scrapper
Teabag
Feather
Painty elastics around a tray, twang
ADD this:
Spice
Sand
Corn syrup
Baking soda ADD vinegar after for fizzy

ADD AFTER painting:
Salt

Can you add to this list?