You need to know your micofiber's "cleaning code," which hopefully you'll find on a tag somewhere on your furniture. The codes are:
W: Use water-based cleaning solutions.
Water alone may work, or you can try adding a little bit of dish detergent. Try to use as little water as possible and blot with a dry towel afterward.
S: Use a solvent based cleaner.
Rubbing alcohol, household ammonia or a clear liquor (like vodka) seem to work well. Use small amounts of solvent on a cotton ball -- don't oversaturate.
S-W: Use the W or S cleaning methods.
The best one to have (you have the most cleaning choices) -- found mostly in more expensive microfiber furniture.
X: Vacuum clean only.
Do not use ANY type of liquid or you'll probably end up with stains that are worse than the ones you were trying to clean!
If the material feels hard after cleaning, lightly brush the area with a soft scrub brush.