There are some good interior cleaning tips and carpet cleaning info in this thread;
http://www.autogeekonline.net/forum...-whats-your-best-tips-interior-detailing.html
Here is what I do without having a steamer or a true extractor.
I vacuum then use a various sized stiff scrub brushes then repeat until I got all that I can get up that way, then start with your cleaners.
I have also recently tried pre cleaning with a vinegar(acidic) solution and it worked well coffee stains.
I did my in laws interior the other day and there were a lot of dark brown stains in the carpet below the center console. I knew they had to be coffee stains and did not want to risk setting them with an APC(basic).
So I first mixed up a batch of water and distilled vinegar(50/50) and sprayed, agitated, and blotted with an old bath towel. Then also did this to any other dark spots also, whether I thought it was coffee or not.
Then I spot treated any dark areas that were potentially oil/grease stains with a citrus based cleaner(I just use non pumice citrus based GoJo hand cleaner). Treat, agitate, and blot.
Then I lightly sprayed an APC or interior cleaner(I use Griots Interior Cleaner) to help neutralize the acidic vinegar solution and to also help remove the citrus cleaner/degreaser. Just a little agitation and thorough blotting to remove the moisture. Or hit it with a wet/dry vac.
I would say try to use a little cleaner as possible so there is less to remove. Keep a spray bottle of water with you. If you have already gave the spot a couple of sprays cleaner and you want to spray more, I say don't. Give it a spray or two of plain water on top and agitate and blot some more.
I did a car a couple of weeks ago that was so saturated with un-removed cleaner that a used car dept left behind. All I had to do was spray with water and agitate, and it would foam up. That turned into a lengthy extraction job.