Three products, three jobs
Leather fails in one of two ways: it dries out and cracks, or it stays wet and rots. The products that address those two failures are not the same, and buying one when you needed the other is the most common mistake in boot care.
Conditioners replace the oils that evaporate out of leather over time. They keep the fibers supple so the leather creases instead of cracking. They do almost nothing for water resistance.
Waxes and greases sit on and in the surface and block water. They condition a little as a side effect. They also darken leather, usually permanently, and soften it, which is wrong for a boot you want to stay supportive.
Creams are the light end of conditioners: they feed the leather, leave a soft sheen, and are formulated not to change the color. They are the right default for anything you care how it looks.
The darkening decision is one-way
This is the part worth being careful about. An oil or grease will darken most leathers by one to three shades and you cannot undo it. On a Red Wing Oro Legacy boot that is exactly what owners want - it is how the patina develops. On a pale tan dress boot it is a disaster.
Test on the tongue or the inside of the shaft, wait for it to dry fully, then decide. The five minutes that takes is the cheapest insurance on this page.
Which to buy for what
One boot, general use: Bick 4. It cleans and conditions, it does not darken, and it is cheap enough that you will actually use it on schedule rather than in emergencies.
Boots that get genuinely wet: Obenauf's LP. Beeswax and propolis, real lasting water resistance, permanent darkening and noticeable softening. Correct for a working boot, wrong for a dress one.
Dress boots and good calf: Venetian Shoe Cream for maintenance, Saphir Renovateur when they need reviving. Both are neutral and both leave the finish alone.
Vegetable-tanned leather: Otter Wax Leather Salve. No petroleum distillates or silicone, which matters because heavier greases can blotch veg-tan and interrupt the patina you are growing on purpose.
What not to use
Silicone sprays seal the surface and stop the leather breathing. Household oils go rancid inside the fibers - olive oil in particular. Saddle soap is a cleaner, not a conditioner, and leaving it on dries leather out. And neatsfoot oil compound, as opposed to pure neatsfoot, often contains petroleum distillates that degrade stitching over years.
None of this is complicated. Clean the dirt off, let the boot dry at room temperature and never near a radiator, put the right product on sparingly, and leave it overnight. Twice a year. That is the whole routine.
