Read the finish before caring for a leather bag
Identify the finish and follow the bag maker's advice before choosing a cleaner or conditioner.

Leather is not one surface
A smooth coated leather, an absorbent unfinished-looking leather and a suede surface can react differently to moisture and care products. The word genuine on a label does not tell you which treatment is appropriate. Find the exact product information or ask the maker to identify the finish.
Do not use shoe polish on a bag simply because both items are leather. Colour transfer and changes in sheen matter on something carried against clothing. Likewise, a household furniture product may contain ingredients unsuitable for the particular finish, stitching or lining.
Bellroy's material descriptions distinguish leather finishes, while its care advice is specific to its own products. Use such guidance for the relevant product, not as permission to condition every leather item in the cupboard. Some finishes need very little applied treatment; others require a specialist approach.
Deal with a wet journey calmly
If the bag gets wet, follow the manufacturer's instructions. Where advised, gently remove surface moisture with a clean suitable cloth and let the bag dry away from direct heat. Do not reach for a hairdryer or leave it against a hot radiator to make up for lost time.
Empty the bag and check the lining as well as the outside. A bottle leak inside may leave a damp pocket long after the exterior looks normal. Keep the bag supported appropriately while it dries, without stretching handles or forcing its shape.
Avoid judging the final colour while the material is still wet. If the maker recommends a treatment after drying, use it only once the surface is ready and according to the product instructions. For a significant spill, unknown substance or delicate finish, ask for professional advice before experimenting.
Make a small test meaningful
When a suitable care product's instructions call for a test, choose an inconspicuous area of the same finish, not a different lining material. Use the specified amount and allow the stated time to see the result. A change that appears acceptable while wet may look different once dry.
Do not mix several products in quick succession. If the finish changes, you need to know what caused it. Keep the product name and the bag maker's advice together, particularly if more than one person looks after household accessories.
Apply only what is recommended. More conditioner is not automatically better, and a bag should not feel heavily coated merely to prove that it has been treated. Follow the directions for removing any excess and for the time before use against clothing.
Store without distortion
Empty heavy contents before storing the bag for a longer period. Use gentle support if the maker recommends it, and keep the handles from being bent sharply beneath other items. Avoid packing the bag so tightly that its seams remain under tension.
Choose a dry suitable storage place and check it during humid weather. A dust bag can reduce surface dust, but it does not solve a damp cupboard. Do not seal away a bag that has not dried completely after use or cleaning.
Leave space between pale and strongly coloured accessories where contact could be a concern. If a mark appears, identify its likely cause before treating it. Rubbing harder may remove part of a finish without removing the underlying problem.
Wear is different from failure
Some leather develops creases and colour variation with use. That is distinct from a strap seam opening, a handle attachment loosening or a closure failing. Inspect those functional parts periodically and arrange an appropriate repair before the damage spreads.
A bag does not need to look newly unpacked to remain useful. The aim of care is to keep it fit for its intended use while respecting the finish it actually has, rather than applying a standard shine to every surface.
Before arranging a repair, photograph the whole bag and the failed area, then ask whether the proposed work will change the lining, hardware or visible stitching. A replacement handle may not match the aged colour exactly. That can be acceptable if the repair restores the intended function, but it is worth understanding before work begins. Keep the discussion specific to the damaged part rather than requesting a complete restoration when only one attachment needs attention. For a sentimental bag, establish which original details you want preserved and which compromises you are comfortable with.