When looking at a shoe, you want to always factor in height, shape of the toe box, height of the toe box, and the manufacturer. It's very important to, again, remember your foot type, range of motion, and flexibility of your foot when you're choosing the height of the shoe.
Most shoe designers are now pushing the heights a little bit higher. The average shoe height is now four to six inches. Also, looking at the heel of the shoe, you want to consider the shape and the thickness of that heel. If you are a beginner at wearing heels, you want to aim for shoes that have a little bit wider heel. The more experienced you become at wearing the heels, you can start progressing to a more thinner, stiletto-type heel.
So, as you look at the front of the shoe, you want to consider the height of the toe box and the shape of the toe box. Height of the toe box is very important if you have any hammer toes or digit contractures, as a short toe box is going to put excess pressure onto the toes. The shape of the toe box is very important if you have the early signs of a bunion or a shifting of any of the toes. The more triangular or narrow a toe box, the more pressure it will put onto the bunion and onto the toes.
As we look at the manufacturer, it's very important to understand that not all shoes are made the same way. So, a size six by one manufacturer can be very different from a size six of another. Always have your foot re-sized every time you buy a shoe so that you can properly match the shoe size with the manufacturer.
If you're new to wearing heels, I recommend starting with a lower heel, thicker heel, and a little bit wider toe box. This increases your stability, and then as you become more comfortable, you can start teasing the height of that heel a little bit higher and going for a more narrow, classic stiletto heel.