I will not only attempt to inform you of what is involved in the many printmaking processes I use but if you have any questions about the detail I will try to answer your queries. AND I will invite other printmakers whose work I admire to share their knowledge, practice and skills from time to time.
My first addition to the page is COLLAGRAPHS, the media with which I work consistently. I'm not going to re-invent the wheel and write the collagraph basics out myself. The next section comes from http://www.artistterms.com.
BUT rather than just copy in the link and let you get on with it I have added detail about what I do. My contribution is in red.
The collage should not be to thick and the materials should not contain any sharp edges as it might ruin both the paper and the press.
Different types of paper and cardboard.
Eg. Tissue paper, crepe paper and japanese paper. The paper can be ripped up or cut and glued on to cover areas in the design.
If using mount board you can start there by incising into the board surface with a sharp knife and lifting out the top layer of paper. For a rough edge you just nick the surface and then pull off the layer.
Any object that can be glued to the plate.
Either pressed into glue/paint to create an offprint texture or glued on to be embossed in the paper when printed.
Acrylic paints and acrylic textures. Glosspaint and varnish.
Different brush strokes will create a variation of texture. Also paletteknifes and sponges can be used.
Or you can press things like leaves or grasses or fabric into them. Experiment by either leaving them there or lifting them to see what kind of impression is left behind. I find texture paste is really good for this. There are cheaper alternatives but they all have their own characteristics and therefore you will get some variation in the way things print. Carborandum is also a good choice if you would like to print something completely black (or any other ink colour)
Other interesting materials can be string, tread, fabric, leafs, peas, rice and masking tape. I sometimes take a blow torch (like the small kitchen ones you use for burning the sugar on top of creme caramel) to burn the plate edges and surfaces. If you are going to do this please take great care, I work out of doors and have heavy duty gloves to hold the plate I and I wear a mask to protect myself. You can get fantastic textures from burning things like texture paste and PVA glue whilst they are still wet because they bubble up and do strange things.