Wax

Beeswax and carnauba wax are the most commonly used waxes in shoe polish, with paraffin wax being used less often. However, I believe Venetian shoe cream is composed of a liquid paraffin mixed with turpentine. All hydrocarbons from paraffin wax to mineral oil fall into the paraffin class.
Venetian Shoe Cream-1

Kiwi lists carnauba wax as the wax ingredient in their standard paste polish.
Kiwi-Shoe-Polish

Other wax options, not as frequently used in shoe polish, are Japan wax and Candelilla wax.

Each wax has a different degree of hardness, which is somewhat reflected in its melting point.

Waxes in order of hardness:

Carnauba Wax: Melting Point (183F), source (leaves of the palm plant Copernicia prunifera grown in Brazil).
Palm

Candelilla Wax: Melting Point (155F), source (candelilla shrub found in Southwest U.S. and Northern Mexico).
Candelilla

Beeswax: Melting Point (145F), source (honey bees).
Beeswax3

Paraffin Wax: Melting Point (140F), source (petroleum distillate – paraffin class hydrocarbon).
Oil_well

Japan Wax: Melting Point (124F), source (fruit of the Rhus Succedanea tree grown in Japan).
Rhus

Some polishes use a combination of waxes.

Mineral Oil

There is some question as to whether or not mineral oil should be used on shoe/boot leather. I can tell you that you should avoid using mineral oil on your shoe and boot leather if you can.

The reason I say “if you can” is because a number of leather conditioners and leather protectors include mineral oil. Fortunately they will typically state something along the lines of “Contains petroleum by-products” or “Contains petroleum distillates” somewhere on the label. Some tanneries also use mineral oil in their fatliquoring process.
neatsfoot oil

Mineral oil is a basic straight chain hydrocarbon and comes is various grades defined by the carbon atom count, which ranges from 18 to 30 carbon atoms. Mineral oil used in shoe products has a molecular composition of about C25H52 (25 Carbon, 52 Hydrogen). Mineral oil is also a non-polar hydrocarbon and as such cannot have a pH value.
mineral oil 1

Mineral oil is also extremely hydrophobic because it is a non-polar substance, and the molecular structure has fewer reactive tertiary hydrogen and carbon atoms which minimizes direct reaction with oxygen. What this means is that mineral oil is much more of a water barrier than triglyceride based oils like animal and vegetable fats. In fact mineral oil is considered to be occlusive (a stop to moisture), whereas triglyceride based oils are considered semi-occlusive (allowing your shoes to pass perspiration for evaporation to some degree). Moisture, trapped in the leather by mineral oil, can lead to dry rot of the leather over time.

Another aspect of mineral oil is how it oxidizes: All oils oxidize over time, even mineral oil. Oxidation at the molecular level can happen in one of two ways: the gain of oxygen atoms, or the loss of hydrogen atoms. Because triglycerides already involve oxygen bonding in their molecular makeup they oxidize through increased oxygen. Since mineral oil can’t really bond with oxygen (for the same reasons it is hydrophobic) it must oxidize through the loss of hydrogen (as a side note: hydrocarbon molecules can be oxidized with oxygen atoms, but only at very high temperatures).

This loss of hydrogen atoms begins breaking down the molecular composition of the mineral oil (originally C25H52) and as it breaks down it becomes more volatile (the molecular composition of naphtha [the petroleum by-product used as a solvent in shoe polish –and other things] can be as big as C12H26). The smaller the size of a hydrocarbon molecule the more volatile (and toxic) it becomes. This is the reason mineral oil is never used to maintain old leather in museums and such.

So why is mineral oil used in shoe/boot care products and in fatliquoring? Mineral oil is used because it is very cheap compared to triglyceride based oils, and it provides a stronger moisture barrier.

Unfortunately, if you plan to keep your shoes/boots longer than a few years, the mineral oil will do more harm than good.

Visual Weight

Vision is very spatial, it is how we judge distance, depth, size and shape, but we also use it to get a sense of weight and balance.
balance

Everything you wear has visual weight and balance (or lack of balance). For example a double breasted suit jacket has a lot of visual weight because of the extra fabric, the additional buttons, and the style itself. Because of this the suit trousers should be cuffed to give balance to the suit from top to bottom.
Double Breasted

An example of visual weight imbalance would be wearing a modern close cut jacket with narrow lapels with double pleated trousers.

This same visual balance applies to your shoes as well. Some shoe designs have a heavy visual weight to them, while others have a very light visual weight.

The visual weight of your shoes should be consistent with the visual weight of your outfit whenever possible.

There are four things that give shoes visual weight, in the following order:
1. The welt and sole
2. The shape of the Last
3. The leather type
4. The shoe style

The welt and sole are listed together because the sole thickness is defined to some degree by the welt method used. And, the welt itself can add visual weight to the sole. You can also get shoes with double thick soles which not only add visual weight, but physical weight as well.

A Norwegian welt has the most visual weight of all, followed by a Goodyear welt. Soles that are attached by Blake stitch, Rapid/Blake, or Bond welted can have a very light visual weight.

Rubber soles also typically add more visual weight than leather soles.

Each shoe manufacturer has a variety of last shapes (some more than others) that vary from round bulbous toe to narrow chiseled toe. The more slender and tapered the last, the less visual weight the shoe has.

Next to impact visual weight is the leather type as follows (heavy to light):
1. Suede
2. Leather with natural wrinkles (like elephant, buffalo, etc…) or induced wrinkles.
3. Embossed grain (like pebble grain, hash grain, etc…).
4. Exotic leathers (like crocodile, lizard, etc…).
5. Shell Cordovan, waxed leather.
6. Calfskin, cow hide.
7. Patent Leather

Finally, the shoe style impacts the visual weight as well. The visual weight of a given style is directly proportional to the style complexity. Basically the more decoration on the shoe the more visual weight it has.

To illustrate the visual weight difference here is a buffalo hide, saddle shoe style, with a bulbous toe and a rubber sole compared to a calfskin, wholecut style, with a tapered toe and blake stitched leather sole.
SaddleShoe
WholecutSide