This post is for the newer generation of photographers who may have learned photography on a digital camera, but are interested in film and printing in a traditional darkroom.
In pretty much any digital editing software, there are filters or different effects to add to your photos. Some of these may add textures, or make your image look like a painting or charcoal drawing. Taking this idea out of digital and transferring it to film, you can also create some similar effects in the darkroom by using everyday objects as do-it-yourself, or make-it-yourself filters. Below are a few ideas...
For this image, a piece of pitted glass was used to create the texture. The glass was placed directly on top of the paper with the image (and texture) projecting through the glass and onto the paper.
For this image, a pair of pantyhose were used to create a softening effect. The pantyhose were cut, stretched, and taped to a matboard frame. The frame was then held up above the printing paper under the enlarger.
The possibilities for items to use to create different effects are endless. Look around your house and see what you can find. Keep in mind that the item you use will need to have some translucency to it, or areas in it that allow light to pass through. You will also most likely need to increase your exposure time, since the light is being reduced by having to pass through another object or material. Some other fun items to experiment with in this way are: fabrics such as crinoline or lace, and plexiglass or plastic wrap with liquids, gels, or powders on it.