I own quite a few of the brushes from ELF (eyeslipsface.com), and am overall very impressed with their quality, especially for the price. The white-handled brushes are $1 and the black-handled brushes from their Studio Line are $3 apiece. Here are my in-depth reviews for the ELF brushes I currently own.
Regular $1 Brushes Mentioned:
Eyeshadow brush - 5 stars
This brush is very soft and fluffy, as opposed to a flat shader brush. It does a great job at picking up eyeshadow (it would work very well with pigments) and packing it onto the lid. It is also great for an overall wash of color from the lid to the brow bone.
Blending eye brush - 5 stars
This blending brush is shorter and denser than most of the other eyeshadow blending brushes I own, which makes it great to build color intensity in the crease. I use this brush to apply the preliminary crease colors and then use another clean, less-dense blending brush to blend out shadows for a softer finish.
Total face brush - 3 stars
The bristles are neither optimally soft nor dense, so the quality is kind of underwhelming on this brush. It is definitely very fluffy and would be good only for applying a very sheer layer of powder or bronzer to one's face. Personally, I don't believe it picks up enough product to use for the application of setting powder, but it could be decent for touch-ups throughout the day. Definitely not an essential.
Blushing, bronzing & blending brush - 3 stars
The bristles are of the same density and texture as those of the total face brush. The angled design makes it ideal for contouring the cheekbones, nose, and sides of the forehead. It could be used as a blush brush, but there are better inexpensive alternatives for that out there. If you want to experiment with an angled brush but don't want to spend too much on a higher-end brand, give this one a try. I know there are probably better variants of this brush out there - I am going to give the Italian Badger angled brush from Coastal Scents a try next.
Concealer brush - 0 STARS!
The brush is too small to conceal anything of notice. It was incredibly poorly-made, with the ferrule detaching from the wooden handle within the first few uses. I used glue to re-attach it, but I may as well have thrown it away given how little I use it. If I ever do use it, it will be as a lip brush for a more controlled application of darker colors.
Studio Line $3 Brushes Mentioned:
Eyeshadow "C" brush - 4 stars
This brush's bristles are slightly softer, shorter and stiffer than those of the $1 ELF eyeshadow brush. Because of the stiffness, it does not pick up color as effectively as its $1 counterpart. I mention in my video review of these brushes that this brush is of decent quality, but it doesn't do anything distinct that any other typical eyeshadow brush can't do - so I just don't see this as a necessity.
Contour brush - 5 stars
Its synthetic bristles are very soft and very dense. It has the same dome shape and stiffness as a pencil brush but is slightly too big to use for that purpose. It applies very concentrated, controlled, intense color to the crease, so I would recommend using it to darken the outer V. Because of its small size and denseness, it is not ideal for blending crease colors (use a fluffier brush for that purpose).
Complexion brush - 4 stars
I swirl this brush in powder to set my foundation on a daily basis. Its bristles are very soft and the design is sleek and sturdy. It could also be used to sweep bronzer from the temples to the cheekbones or to provide a slight contour. My only complaint is that I had expected the brush to be a little stiffer, for a more controlled application of powders (something like the MAC 134). Because the brush doesn't offer the stiffness I had expected, it applies powder in a very sheer layer.
Blush brush - 5 stars
The same soft synthetic bristles and sturdy design are featured in this flat blush brush. I personally think the brush is too small to use for the application of blush, though it is a matter of personal preference. This brush is ideal for sweeping a highlight color from the top of the cheekbones to the temple, and down the center of the nose. It picks up the perfect amount of product and its soft bristles make blending effortless. It has become an integral part of my daily face routine.
Powder brush - 5 stars
I use this brush to stipple on liquid foundations and then blend it out for a glowing, airbrushed finish. It is a very dense, soft, flat-topped brush (probably comparable to most flat-topped buffer brushes out there). Unlike your typical stippling brush (e.g. the MAC 187), which has white bristles that are not dense, this brush is full all the way through, which I believe prevents the streaking effect I sometimes get with a stippling brush. It would also be excellent for buffing powder foundations or setting powders into the skin.