Carpet cleaning is one of the most tiring cleaning tasks. I would also like to contribute my tips here:
> Stains in carpet should not be rubbed. This spreads the stain, further. Just dab it using a towel, clean cloth or a sponge
> Shaving cream works! Apply it on stains and after sometime, remove it with a cloth. Finally, spray a little bit of vinegar+water solution on it
> If a gum is stuck on the carpet, ice-cube can be used to freeze it for some 30 mins and then you can easily remove it
> Wax stains on carpet can be removed if you melt it again. Just use a cloth and iron it on the stain, the wax eventually melts. Remove it with a butter knife
> Use club soda to remove wine / beer stains. Allow soda to soak on the stain and just remove it with a cloth
> Steam cleaning the carpet on a regular basis, keeps it clean and well-maintained