The second big garbage disposal issue is what can go down the disposal. Some will say nothing (so why have it) and some say they put everything down the garbage disposal and never have a problem. Of course, some of this depends of the size and power of the motor in your unit. What does not belong in a garbage disposal other than the obvious; silver wear and fingers?
Grease and fatty materials even if liquid when dumped in the unit can solidify and cause problems. If this material gets past the unit it can also plug drains.
Stringy vegetables such as celery, asparagus and rhubarb can wrap around the blades and cause the unit to run slow or stop. This also applies to tea bags if the string is attached. Even banana peels can get stringy and wind around blade. Starch vegetables such as potatoes can become past solidify and plug the unit and pipes.
Noodle and rice can continue to expand in drain even if cooked and particularly if they are uncooked.
Coffee grounds will go through the unit but will not be ground up and can settle in traps. No bones should go in.
Even soft bones can shatter and wedge or cause small marbles that will bounce around making noise and never leave.
Pits or hard seeds such a peach pits.
Hard vegetable ends like carrots, onions and garlic can be as hard as bones and have the same problems. The garlic and onion will also leave an odor.
Artichoke leaves can be particularly difficult.
And lastly napkins or paper towels will both wrap on the blades and is they are ground up can cause a paste that can gum up the works.