Mix 2 parts wallpaper paste and 1 part paint. It isn't necessary to measure -- just eyeball the amounts. It should have the consistency of pudding. Using a large brush, apply the mixture to an area approximately 16" by 16".
Still using the same brush, immediately begin stippling over the wet mixture. To do this, "pounce" the end of the brush up and down over the entire area. Use a cotton rag to begin the ragging-off process. First fold the cloth in one hand so that all the ends are tucked in (otherwise they would drag in the paint and spoil the effect). Then apply the cloth to the painted area and pick it straight up, moving some of the paint off. Continue over the entire area, turning the cloth as you work so that you're always using a new part of its surface. As the rag absorbs the paint, keep refolding it to expose more clean cloth. Try to work in circular motions as you rag.
Continue applying areas of paint to the wall, overlapping the previously ragged areas as necessary -- you or your assistant can always rag over the seams to blend them in. When you get to chair rails or molding, make sure the tape is firmly pressed down so you can work right over it without getting paint on the trim.
When the first coat has dried completely, mix a second coat of paste and paint, this time using equal amounts of each. Repeat the process of applying, stippling and ragging off. This second coat adds depth and richness to the walls. It also smoothes out the look and fills in any gaps left in the pattern.