Besides dry-cleaning, which needs to be done only once a year, there are a few other things you can keep in mind to add longevity to your suit's life.

Hanging device, the right hanger preserves the shape of the suit. The hanger should mimic one's shoulder profile, which preserves the shape of the tailored collar and drape. The shoulders of the hanger should have a generous thickness, to ensure that jacket shoulders maintain their shape, and a strong metal hook. While hanging, hang suits few inches apart to reduce squashing it out of shape.

Cleaning device, the bristle brush is a great friend of the suit, helps to remove stuff that clings on to the fabric. Besides the bristle brush, the lint remover is a quick solution to visible fluff, pet hair and dandruff. Essential tools to have in your wardrobe.

 When worn, its best to keep out of the rain. A fused lining, a cheaper and less labour intensive option for interlining suits, will pucker and become out of shape when wet. Once this happens, no amount of ironing can bring the suit back to its original condition.

When stored, use suit bags. The bag protects it from dust, insects and from fading. The moth larvae that are invisible to the eye, can cause damage to your wool suits, as they feed on keratin, the natural protein found in the wool. Dry-cleaning before storing will get rid of these moths and the eggs. 

Rotate your suits between wears, this helps it to relax and restores its shape. 

It's totally upto you how long your suits are going to last.

Happy reading.