The first reason, I believe, is people have the misconception that dolling shoes means following the foot on the base. When in reality, shoes often change the shape of the foot instead of the other way around. Shoes have a hard rubber sole, and while, yes, they do have fabric on them, that doesn't determine the shape of the shoe at all.

What I usually suggest is to go get your favorite pair of shoes and put them on your feet, then lean a mirror against the wall and look at how your shoes wrap around your own feet.

You're probably going to see that the sole of the shoe is stretching the fabric over the tops of your feet, BUT, the shoe doesn't actually interpret the shape of your foot. Think about it, does your shoe hug your feet? Does it look different on and off them?

So to start with, DON'T BE AFRAID TO STRAY FROM THE SHAPE OF THE BASE'S FOOT. I do it all the time. Even though I make my bases with shoe-shaped feet, I STILL don't follow that shape directly.

Here's a good example of what I'm talking about. While it's not noticeable, as I didn't stray far from the base's original feet, I still left a bit of room in the toe of the shoe, and I also made the heel a bit rounder than the foot.

This example shows shoes in different positions. For example, let's look at the sneaker on the right. The foot is bent, and so because of that the shoe is also bent. There is a line you can end up crossing with this, though. A shoe's sole will only bend so far before resisting. Chucks are pretty versatile that way, so they go pretty far, but if he was wearing a boot or high heels, where the sole is a lot stiffer, that kind of movement would be extremely painful as the weight of the foot would be resting on the toe instead of on the pad of the foot.

The boot is just another example of straying from the original base.

Also, it's the first example of the boot in this tutorial.

The previous example was of sneakers, which have flat soles, with only a little bit of curving to accomodate the curve of the foot.

Boots are a lot sturdier than sneakers, and are designed differently. Most boots actually have a small heel, like in this example. Even men's boots!

I can't actually tell you if this is just a style thing, or if there's an actual ergonomic purpose to the heel, but it's there, and for realism it's a good idea to include that heel.

Here's an example of cowboy boots. While I included the top, I want to focus on the sole of the boot for the moment. Notice how it curves with the foot across the pad, and then there's like a cut into it towards the heel? A lot of boots are basically on a small incline like that, with a chunk missing between the heel and the pad.

If it helps, I suggest googling images of boots to get a better idea of what to do and where.

Now, most boots have a rounded off toe.

Like in this example (where again, I ended up not following the actual foot).

But let's talk about high heels. I know A LOT of people will still follow the shape of the foot for these, when NO NO NO YOU SHOULD NEVER DO THAT.

High heels completely change the shape of the foot, unless the base's feet are designed to wear high heels, just disregard the feet completely and draw the shoe.

The only things to remember for high heels are the toe, which should at least be as long as the toes and half the pad so that the doll isn't standing on it's toes uncomfortable like, and the heel, which should be pretty substantial for the actual high heel part.

Also, DO NOT point the high heel out. All heels point inward a bit towards the toes of the feet. Heels are round at the top, kind of like the right half of an upside-down tear drop (or left half--whatever).

Here are a bunch of examples of what I'm talking about.

Make sure the heel is long enough to actually make sense for the rest of the shoe, and keep it at a decent angle so that it doesn't look like one step will break that shoe.