The best beard comb choice depends on what type of beard you have. Different types of combs work best depending on beard shape, beard length and facial hair texture. For each of those three things, different comb sizes, shapes and materials might be better than others. You might also wish to base your beard comb style on whether you plan to use it with scissors to trim your beard.
Beard size and shape can vary. A long, full beard will be easier to groom with a wider comb that has thicker, more widely spaced teeth. On the other hand, mustache hairs will be better served by a smaller comb with finer, more narrowly spaced teeth. Keep in mind that when grooming a beard, you might need to untangle your hair before you can really comb it, so you might need two combs.
Untangling your beard hairs before combing them will not work well with a fine comb and might require you to use your fingers. Widely spaced teeth work best at this stage, but after the tangles are gone, you might need a finer comb. The finer your facial hair, the finer you'll want your comb teeth. Thick and curly hair might never be easily groomed with a fine comb, just as fine and straight hair might never be neatly groomed with a coarse comb.
A good tip for determining the thickness and spacing of beard comb teeth is to find a conventional hard rubber barber's comb — one that has teeth tapering from thick and widely spaced to fine and narrowly spaced. With this type of comb, you can choose the best section to use for grooming. These types of barber's combs usually are inexpensive and might be the only comb you need, but keep in mind that very fine teeth on conventional combs might scratch your face.
Facial hair that is limited to a mustache, goatee or soul patch might require a comb with finer teeth. Smaller mustache combs are easier to carry in your pocket, and some beard combs can be folded like a pocketknife for this purpose. If portability is a factor when choosing the right comb, make sure to consider smaller sizes.
Another comb shape factor is the handle. Some combs have them; some do not. Whether a handle makes it easier to groom your beard is mainly a concern only if you plan to trim your beard with a comb and scissors. The best combs to use for trimming a beard with scissors have a handle and a contoured shape.
A contoured beard comb makes it easier to align your chin and mustache hairs while cutting them, and a handle helps with control. These specialty combs are excellent for trimming, but the process takes practice. Note that the length and spacing of the teeth on a contoured comb might not be ideal for all grooming needs.
Finally, it might be helpful to compare materials. Certain rubber combs might seem too flexible, and certain plastic combs might be too stiff. A beard comb made of natural horn is usually more expensive but is reputed to help control static. You might need several combs for different purposes, and picking the right comb involves trial and error, so it would be wise to read as many beard comb reviews as you can find before making your decision.