i made some lovely baby face/body paints with organic lavender baby lotion (on offer in my local shop) mixed with a sprinkle of powder paint or cocoa powder and a squirt of washing up liquid. smells lovely and just rubs in.
also they loved flour in the builders tray, add sparkly glitter, sieves, pots and spoons or cars for making tracks in.
shredded paper or collage materials to explore
feathers
baskets of balls in different sizes, cardboard tubes for rolling them down - I put these in a tuff spot for babies to crawl in and explore with bits of drainpipe too.
silks, soft fabrics, mirrors for peekaboo games - extend with hats, bags, sunglasses and shoes
what about a sensory den, use drapes or cardboard boxes, add lights, and a few props to explore and hide
hope that gives you a few ideas - i love this age group