Always store your glasses in their case when not being used. Do not leave them lying around without a case. Glasses left outside of their case get stepped on, knocked around, sat on and chewed up by puppies/kittens.
Step2
Wash your glasses on a daily basis. Use diluted dish washing soap and warm water to wash the entire glasses: frames, nosepads, hinges, screws, lenses. For further detail on proper way to wash glasses there will be a link to the article below.
Use both hands to put your glasses on and to take them off. Try to avoid the one handed method. Using only one hand to take them on and off causes frames to get out of alignment quickly.
Step4
Visit your vision clinic's optical every 3 months for a tune up. The opticians will tighten any screws that's coming loose and check the frame alignment. Even careful glasses weares/users require tune ups every 3 months.
Step5
Do not keep or store glasses in your car. On bright sunny days, the heat created inside the car can cause warpage and distortions to the lenses.