Similar to marbling, paste paper begins with a methyl cellulose mixture of powder with water.  Many people cook their own pastes and swear by them, I go for ease of preparation.  Once the powder is fully hydrated, the paste is divided into roughly 1/2-cup portions into small containers.  Each container is then tinted with the acrylic color of choice.  The beauty of the extender paste is that it takes very little pigment in order to produce vibrant colors.

For a session of creating paste papers, I place my materials as follows:  the paper to be decorated in a stack to the left with space in front of me for working on each individual piece.  The colors in bowls are arranged in front.  Several paint brushes are to the right of the colors, as well as a container of water.  A small dish of water and a sponge is to the left for moistening each sheet before pasting.  A drying rack is to my right, or sometimes I hang a string across the room.

The paper you use can be text-weight, gift-wrap-weight, card stock (makes a great postcard!), and can be white, solid color or patterned.  I have also used this method on stretched, prepared canvas as a background for a framed wall piece.

Tools for patterning can include:  decorative paint rollers, large stamps (not finely detailed), decorative painting combs, hair combs, toothpicks, bamboo skewers, cardboard cut with a decorative edge, sponges--anything that will "disturb" the surface of the paste.  The piece below (which is part of an altered book and is mounted in 2 sections) was painted in light pastel colors and allowed to dry.  Then it was brushed over with slightly darker colors and stamped into with an allover leaf design which removed the surface color.    By the way, the "Lonely Dories" (w/eyes), fir tree, garden gate and pink fairy are hand-carved.

Moisten your paper with the damp sponge, select a few colors and brush a fairly thin coating of paste to your paper.  This can be brushed across the paper, in small sections, however you like.  Just don't pour on the paste thickly.  Once the colors are applied to your liking, take your tool and draw it across the paper to make a pattern.  Experiment, experiment!  If you don't like where it's headed, take your brush, smooth the whole thing over and start again.  It's very forgiving.

Some of my very favorite papers are those that have some sort of surface patterning already:  marbling, decorative commercial papers, previously-pasted papers, paint-spattered papers, dyed or sponged papers...  Don't limit yourself!

Once you are finished with the pasting, hang to dry, either over a string or on a rack.  They do take up to overnight to dry, depending on the humidity.  They may be pressed with a warm iron after dry, but this isn't usually necessary.

As for using paste paper, it is appropriate for any way in which you use paper:  note cards, backgrounds for journal pages and altered books, book covers, book end-papers, and any kind of collage.