On our shelves (January)...

Cross-posting from my Pre-K blog; here are our Montessori-inspired work trays that the boys and other preschoolers were using in January:

Writing letters in salt; although, honestly, the kids like using this as a sensory box as is--but to make it more fun, you could add some winter animals instead

Dot letters

"Ice block" building (i.e. sugar cubes) and winter animals (you can often get these at Michaels & use a 40% coupon)

Pouring tray with water and ice (ice has been a popular addition! Fun to see how much it needs to melt before it slides down the vase)

Cutting snowflakes; I folded coffee filters and clipped them to hold the folds together while cutting 

Art tray: stickers, snowflake stamps, and markers (I'm hoping to make this more interesting as the month moves on, but we'll see)

Number picture puzzle; printable from here

Sensory bin: various white fabrics, white duplos, and cotton balls with animals from the winter toob

Patterns; printable from here

Playdough

Cornstarch+water