Rule #1Keep your clock in a place that has the same temperature and humidity you enjoy. For most of us, that would be our homes. Do not set your clock next to a source of heat or in a place where it will be subject to drafts or direct sunlight.
Never store your clock in the attic, the basement, or the garage. These places offer extremes in temperature and humidity your clock will not like.. The joints of an antique clock are held together with hide glue. Hide glue softens with heat and if a clock is kept in a place like this, the wood in the case will expand and contract. These factors will cause the joints separate. Your clock could also experience loosened veneer, corrosion in it the movement, and whatever damage bugs and other critters might leave behind.
Rule #2A mechanical clock is a machine. As such, it requires periodic cleaning and lubrication. The primary cause of a clock stopping (other than being knocked to the floor) is a build-up of dust and oxidation in the pivot holes of its movement. These are points upon the wheels turn and must be lubricated with clock oil. However, oil has a tendency to collect dust as well as oxidation from the metal it lubricates. Harder bits become embedded in the softer brass plates and grind way at the steel pinions on which the wheels turn. As the oil thickens, the clock eventually grinds to a halt.
By the time the clock stops working, damage has already been done. Some of the brass pivot holes will become egg-shaped with time. Regular cleaning can slow this process but not eliminate it. Most pivot holes can be easily re-bushed when needed. However, steel pivots are not as easy to repair and regular cleaning will greatly extend their life.
Frequency of servicing depends upon the type of clock. Mantel and wall clocks should be cleaned and lubricated every 5 years. Grandfather and anniversary clock can go for 10 years before they need to be serviced. Please know that adding oil to a dirty clock will not solve the problem. The dust and oxidation must be removed to keep the clock in good working order.