Sensory bins are one of my most favorite ways to facilitate learning in children.Creating a sensory bin is so fun and so perfect because you can tailor it specifically to your child or children.
Sensory boxes are for year round use, indoors and out, in any weather. Over the years I have created many colorful and stimulating sensory bins to keep little ones happy, engaged and learning.

DIY RED Sensory Box

You can use a multitude of fillers for your box:
red shredded paper
red Quinoa
red pasta
dyed rice . . .
But you dont have to do a red filler for a red box because the items are red,
so the backdrop could be whatever neutral color you want such as; sand, beans, pasta, oatmeal, rock, cornmeal . . .

TIP : I like to mix sensory fillers so that there is more to explore, and because bigger fillers
such as shredded paper, can be easily separated from smaller ones such as rice!

Once you have decided on your filler you are now ready for your items!

Try to get a collection of natural items like;
rocks, wood, fabric, twigs, pine cones, shells, leaves, grass, seeds . . .

TIP : You can color wash natural items such as wood, rock and shells to make the colors you need.

Get something to scoop with (spoon) and something to scoop into and our (cup).
If you can, get tongs for pincer strength while sorting small objects.
Add small lids (from water bottles) or ice cube trays to sort and hold small objects.

Now, add the RED items.
The secret is to get multiple items with various textures, shapes, sizes and amounts.
You want your child to be able to find and create patters (big, bigger, biggest, for example)
and have the sensory box sustain their attention.

You can get items from around the house, like the “junk” drawer and the bottom of the toy chest.

You can go to second hand stores and find little objects (usually in bags of mismatched stuff).

The BEST place to find objects is the Craft Store and Party Store!

You can paint objects that are a different color with spray paint or acrylics.
Flash Cards, Scrabble Tiles, Geometric Shape Pieces and other learning materials are great.
Use pictures, letters or words from books and laminate them.
Cookie cutters are fantastic because they encourage children to crunch down into the filler and experiment with making shapes, using pressure and more!
Use scented items or spices in small jars (cinnamon, apple, cherry) that are associated with the color. 
TIP : to tailor the experience to your child, you can paint numbers, shapes, letters and words on wood blocks or rocks!

TIP: Want to teach your child their phone number or address? Use a sensory box where they arrange the numbers, or match the address to a picture of your home!

TIP : Keep your items and fillers separated in plastic bags or containers, then you can use one big bin / tub for your various themes and mix and match items and fillers as you create new ones!