Vegetable-tanned leather ages, it doesn't wear out. Belts, a leather cuff, gloves and a good tote all darken and develop a patina from your hands and the sun. That's the leather doing what it should — the job is to keep it fed so it stays supple while it ages.
Wipe, then feed. Dust and wipe with a barely-damp cloth, let it dry naturally, and a few times a year work in a thin coat of conditioner or a neutral cream. Over-oiling is a real mistake — it darkens leather unevenly and can leave it limp — so build it up sparingly.
Keep it dry and stuffed. Store a leather bag with something inside to hold its shape, ideally in a dust bag, never sealed in plastic where it can't breathe. If any of it gets soaked, blot it and dry it slowly away from heat before conditioning.
Deerskin gloves want gentle handling. Work them on finger by finger so the seams don't strain, let them air after a wet day rather than drying them on a radiator, and a light leather balm keeps them soft. Never machine wash leather gloves — it stiffens and shrinks them.