There are a few things to consider when choosing a veil- width, length, cut, color, and what types of embellishments you want. I will explain each of these in greater detail below...
Width:
The width of the veil is determined by the width of the fabric before it is gathered. Veils typically come in two standard widths- 108" and 72" wide. Basically, the wider the veil, the poofier it will be. Most veils are 108", but if you are going for a simpler look then the 72" size might be the way to go. Veils can be made out of any width fabric, so if you want something even fuller than 108" or slimmer than the 72", then some veil companies will make custom changes.
Length:
There are lots of different lengths to choose from when picking your veil. The exact measurement differs based on your height, so they will either order a standard measurment (each company's are different) or they will do a custom measured length.
Chin length
Chin length
Chin length is most typically seen in a Russian or French netting style, but can sometimes also be seen in tulle (like the one pictured) and can be worn either as a blusher or as a veil. It is best paired with sophisticated, minimalistic gowns.
Shoulder length.
Shoulder length is a lesser common style, but can still be really pretty. It is best paired with less formal styles.
Elbow Length
Elbow length is a very common style. It is best paired with gowns that don't have a lot of detail on the back of the dress and don't have a definitive waist seam, such as a plain mermaid or sheath style (like the style illustrated below). The reason is that the veil creates a line across your back and can detract from pretty details on the back of the dress and can also cut you off in a weird spot, making you look shorter or wider than you really are.
Fingertip Length
Fingertip length is a great length because it is a short style but doesn't cut you off like elbow length does. It is also versatile as far as what styles it works best with. It can be paired easily with simple or more formal styles, as long as it hits about an inch or so below the waist line of the dress. Otherwise you run into the same issues as you do with elbow length.
Knee Length
Knee length is another versatile length that works well with many styles of gowns. It is long enough to not disrupt the details on the back of the dress, but short enough to be out of the way. Just make sure that it isn't cutting off any of the pretty train details.
Floor Length
Floor length is great because you aren't cutting off the dress in a strange spot, but you can continue wearing it at the reception without it getting trampled. It works fine with pretty much any style.
Chapel Length
Believe it or not, chapel length is actually one of the most versatile and flattering veil styles. Because it hits an inch or two past the train, it doesn't compete with the back of the gown at all. It blends right into the dress, allowing the pretty details on the back of the dress to show through. It works great with any style, even less formal ones (just embellish the veil accordingly), just as long as the train of the dress is an inch or two shorter than the veil.
Cathedral Length
The same rules apply to cathedral length as chapel length. It looks gorgeous with any style (including less formal styles), just make sure it hits at least an inch or two past the train of the gown.
Shoulder length.
Shoulder length is a lesser common style, but can still be really pretty. It is best paired with less formal styles.
Elbow Length
Elbow length is a very common style. It is best paired with gowns that don't have a lot of detail on the back of the dress and don't have a definitive waist seam, such as a plain mermaid or sheath style (like the style illustrated below). The reason is that the veil creates a line across your back and can detract from pretty details on the back of the dress and can also cut you off in a weird spot, making you look shorter or wider than you really are.
Fingertip Length
Fingertip length is a great length because it is a short style but doesn't cut you off like elbow length does. It is also versatile as far as what styles it works best with. It can be paired easily with simple or more formal styles, as long as it hits about an inch or so below the waist line of the dress. Otherwise you run into the same issues as you do with elbow length.
Knee Length
Knee length is another versatile length that works well with many styles of gowns. It is long enough to not disrupt the details on the back of the dress, but short enough to be out of the way. Just make sure that it isn't cutting off any of the pretty train details.
Floor Length
Floor length is great because you aren't cutting off the dress in a strange spot, but you can continue wearing it at the reception without it getting trampled. It works fine with pretty much any style.
Chapel Length
Believe it or not, chapel length is actually one of the most versatile and flattering veil styles. Because it hits an inch or two past the train, it doesn't compete with the back of the gown at all. It blends right into the dress, allowing the pretty details on the back of the dress to show through. It works great with any style, even less formal ones (just embellish the veil accordingly), just as long as the train of the dress is an inch or two shorter than the veil.
Cathedral Length
The same rules apply to cathedral length as chapel length. It looks gorgeous with any style (including less formal styles), just make sure it hits at least an inch or two past the train of the gown.