>>640190Leather care is a bit controversial now with all the different products (and the manufacturers not explaining it objectively), but I like the way altberg explains it.
http://www.altberg.co.uk/leder-gris/bootcare/Basically, your boot leather needs
-fat/oil which enters the leather,keeping it supple and waterproof, but removes breathability and can make it too soft if too much is used
-wax, which remains on the surface mostly, protects the leather and repels water
Note how they offer two products, one for general care with a high content of wax and low content of fat and one for restoring particularly dry leather with more fat. You're supposed to keep the leather in the sweet spot of fat content to remain supple but not weak and replenish the wax coating regularly.
Almost all shoe polishers and leather care products will have both, but it'll be hard to tell the composition. I assume leather conditioner will be basicallx fat/oil or a substance of similar effect that will usually not build a coating (you don't want that on a leather jacket or something...)
I would suggest to just get a normal boot leather care product with both parts and treat it regularly. Having too much wax can look funny but is ultimately harmless, too much fat willl make the leather weak, so take caution. If the leather ever starts looking dry, apply more or apply fat/oil/etc. separately.
Also, before applying anything to the leather, it should be absolutely clean and dry. Greasing up dirt will not do the leather well.
Goretex Leather boots are not supposed to be treated with fat/oil since these remove breathability and clog the membrane. However, the resulting treatment with wax or nothing at all is adverse to longevity. I also don't believe the breathability of waxed leather over a membrane is useful any more (dunno why manufacturers still produce GTX boots...)
tl, dr: always clean before doing stuff, apply *something* regularly, apply conditioner when really needed.
