Leather is a natural product. Good quality leather can have a classy, prestige look. And other types of leather, like old biker jackets, can have a rough and rustic appeal. But as a natural product leather requires some care, lest it degrade over time.
Keep leather out of the Sun.
Leather will tend to crack in heat or UV light. Some leather treatments will reduce this; quality handbags and clothing tend to be quite resilient to sunlight; occasionally an item might look good with a little sun damage. But leather furniture will quickly be damaged with sun exposure; even when furniture is indoors sunlight through windows can be an issue. Consider getting your house windows UV tinted, use drapes, or move furniture away from the windows.
Keep leather away from moisture.
Water can cause mould and mildew to grow on leather. This is a bigger issue with organic products as the growth will not be confined to the surface as it is with plastics; mould will cause the leather itself to deteriorate. Leather needs to be moisturised, but not with water.
A cool, dark area is the best place to store leather. This storage place should ventilated; avoid plastic or airtight containers
Keep leather moisturized with leather cream or leather dressing; some products respond best to waxes or oils. Check with the manufacturer for their recommendation. Moisturize the product even when it is not being used.
Clean leather with a damp cloth; microfiber cloths are particularity good for this. Check for any dirt particles on the leather before cleaning, as grit can cause scratches. Always allow the leather to fully dry.
Never use solvent on leather; most cleaning fluids sill cause the leather to dry out and crack, damage that can never be fully repaired. Stick with water.
Avoid scuff marks or stretching.
Unless you like the look of worn leather it is best to avoid any sharp or rough that can damage the surface. This includes items such as belt buckles, some shoes and studs on clothing that can scratch leather furniture.