Always vacuum a chair or couch before you start the rest of the cleaning process. Otherwise, it is possible to cause more staining, since you will be adding moisture to whatever is already there. If there are any dried substances that can be broken up a bit. Carefully do so using your fingers, and then vacuum again.
If any spots are from recent spills you might still get some of the material off with a rubber spatula or the edge of a spoon. Be careful with the more delicate upholstery fabrics, and be careful not to spread spots in any case. If you are cleaning cushions that can be removed, take them to an area where you can work on them without introducing more dirt; a clean garage or a kitchen floor, for example.
For the Upholstery Cleaning itself, you can use a mild dish detergent and a small scrub brush (a toothbrush can work for small stains). Mix two tablespoons of detergent into a cup of water and put it in a blender. Blend until you have a frothy foam.
With a soft brushwork a little bit of the cleaning solution into the stain. You should see some of the dirt or staining material lift up into the foam. You can carefully scrape away the dirty foam with a spoon or rubber spatula. Then repeat the process if necessary. Be careful not to use too much of the cleaning solution and don't let it spread too far.
Drip some fresh water on the spot to rinse out the soap, and soak this up with a clean white cloth. repeat this several times to remove as much detergent as possible. If you have a wet-dry shop-vac it will be more effective than a cloth for removing the solution. Just apply a bit of water, suck it out and repeat.
That's how to clean upholstery, but you aren't done yet. It is important to dry the material quickly. If you have that shop-vac, suck out as much moisture as possible. Push on the area and dab out moisture to the extent possible with a clean white cotton cloth or undyed white paper towels. After this, place a fan where it will blow some air across the spot, and leave it there for an hour or more.
How to Clean Upholstery - Other Tips
You may want to try this whole process on an inconspicuous part of the furniture first, to be sure that the material is color-fast.
If your homemade cleaning solvent doesn't get the job done, you can try some of the commercial Upholstery Cleaning. Be aware though, that it often contains toxins such as acetone or nitrification acid. Wear gloves and be sure you completely rinse the cleaned area.
Finally, if you cannot clean upholstery sufficiently by yourself, call Fresh Upholstery Cleaning Melbourne. Almost all carpet cleaners also clean couches and chairs.