This is a question regarding the tartar removal cycle.

Even though I brush my teeth consistently 2 to 3 times a day, I tend to get tartar easily.
I've been told to get a scaling done once or twice a year, but does it vary greatly from person to person?
I wonder if it is actually true that someone has a constitution that is prone to tartar formation.
I've heard that getting scaling done too often weakens your teeth. Is that true?
I would also like to know if people with weak gums need to receive treatment more frequently.
Are there any additional care methods that can help prevent tartar?