Just about every graphics program has the ability to use and create custom brushes. However just because the title of a set of brushes has the word "Vector" in it does Not make it capable of creating vector artwork. Below are some Do's and Don'ts of vector brush work:
Don't use photoshop brushes when creating vector pieces. Photoshop brushes can only create Raster based images! If the brush pack has the word vector in the title this is just the brush artists point of view. This is what the creator of the brush set interprets vector as. These "Vector Brush Sets" usually consist of circular objects, swirls, and quite often silhouetted figures in various poses. Now where as these can make for some pretty interesting effects these do Not belong in vector artwork. Photoshop brushes no matter the size can only be taken to their 100% value (what ever that may be) before becoming pixelated. This is because these brushes can only ever produce a raster output. This being said even if you use the pen tool included in photoshop or some other raster program to great a shape then "stroke" the shape with the brush tool creating an outline, this also is not a vector even though you used a vector tool. The end result is creating a raster effect, and as such renders it useless for vector work.
Do use brushes created for vector programs such as Illustrator, Freehand, Corel Draw, and Flash. These brushes are made from vector shapes and are perfectly scalable to any size without loosing quality.
Don't use them! Filters work by taking a raster image and applying an effect to the image. The special effect can take the form of simply shifting a pixel to the left or perhaps adding a frame or changing the color of a pixel or adding an emboss to an image. A lot of you prefer to create vector art in photoshop. And where as there is no problem with this (photoshop can easily create vector based works using the pen tool and vector shapes only!) some people tend to get carried away, and by the end of the project they have applied drop shadows, added grain or any other filter/effect and the image is no longer a true vector. If anyone is paying attention, the reason for this is because it takes a "raster" image and applies the filter to it. Since vector works cannot include raster images... well I think you get the picture.
Do not use filters. Did you not hear me the first time? Filters are raster based, and cannot be scaled without changing appearance, or becoming pixelated. Seriously though, these effects can usually be achieved with true vector means. Shadows can easily be made with gradients, glows as well. Bumps, bulges, streaks, and any other filter can easily be recreated in a vector program with a little extra work and patience. Now for the confusing part. There are some filters available in vector programs that will let you create true vector effects, and there are some filters that will do the same as it would in a raster program. In illustrator you can create a simple 3D "extrude" or "revolve" as they call it. This will let you take a path and then by a process called blending, will create a simple editable 3D object, complete with highlights and shadowing (not cast shadows). I know a few programs are capable of a filter called "Live Trace" (Illustrator and Flash to name a few). This filter does just as the name implies. I will explain further in the next section. Just about all programs are capable of text effects as well.
Don't use raster textures in your vector work. Blending a raster texture over a somewhat boring piece may seem like a quick fix, but raster images have no real place in the vector world. Noise and textures can also be easily created in a vector program. There is no excuse to take the easy road and apply a raster texture over an image and changing the blend mode.
Do use vector textures. Just because you can't use raster images to add depth and texture doesn't mean you cannot use textures in general. A really easy way to achieve this is to use gradients, vector patterns, or live trace. Live trace is essentially a filter that takes a raster image and converts it to a vector image. It finds different colors and automatically creates (traces) the path work to correspond to each color or line. If you are looking at this for an easy way to create a vector portrait or full piece of any kind, think again. Live trace, as convenient as it may be, is not capable of getting intense detail. Vector artists generally use this very sparingly. If I think something may look better with some texture I take a raster image and create a simple black and white live trace of it, essentially creating a vector texture. I then change that to any color or gradient I wish and place it in the piece. There is never a circumstance where I would recommend you using this tool to create your full piece. In conjunction sure, great! By it self, no way.
Do browse the Vector Resources Gallery. Some amazing works in there... and best of all, they're Free.
Don't hesitate to contact me. If any of this is confusing and you need a better explanation please feel free to drop me a note. I'll be happy to speak with you one-on-one to help clear things up.