OMG everyone NEEDS the 224 brush. LOL
Seriously it is my favorite brush. I use it everysingle day. I use it to apply a brown "backgound" wash to the area between my browbone and crease. and I use it for blending after I've applied all of my eye colors. I love love love that brush.
You can also use it to set powder underneath your eyes after applying concealer
And you can use it to contour the small areas on the sides of the nose (I've never done it but i saw it on youtube lol)
You can use it for the crease too but it will be more of a wash of color instead of a concentrated area
You can use it for just a wash of color all over the eye if you were going for a simple look
Seriously i love the 224. Can you tell? ha ha