Summarize the following:
If you are buying bettas to breed, make sure to get them only from one specific, reputable breeder. This can help ensure the quality and success rate of your betta spawn.  Be aware that getting quality bettas to breed can be expensive. More expensive fish generally mean that a breeder has also used selective breeding techniques. Although this isn't a guarantee of successful breeding, it can ensure the health and quality of your fish and possible their spawn. Some elements to look for in a breeder include: accomplishments, longevity, experience, knowledge, professionalism, affiliation with betta organizations, availability, reputation, track record, cleanliness, reference.  Ask the breeder to let you know about the parentage of the bettas. If he can't answer the question, you may want to consider using another breeder that keeps tabs of his bettas' parentage. Find quality betta breeders through organizations such as the International Betta Congress. If you have friends or family that breed bettas or are familiar with them, you might ask them for suggestions, too. Figure out which bettas to get depending on what qualities you're hoping to highlight or breed out. You want to get the best quality stock you can afford and finding the right pair can help ensure health, beauty, and even your enjoyment.  Make sure that you and your breeder both have knowledge of your fish's genetics. Knowing which traits can be inherited is important for responsible breeding to prevent  generations of fish that follow from being unhealthy. Be aware that selective breeding is meant to bring out certain characteristics in a betta fish. For example, you may want to bring out black lace patterns in your betta. By choosing another betta with more distinctive lace patterns and mating it with your betta, you can bring out this particularly quality. You can apply this principle to color and fin size, too. Remember that if you're hoping to achieve a certain goal through your selective breeding, either with fin size or color, it can take a few years and cycles for these traits to fully appear.  You can either use hybridization or inbreeding for desired traits. Hybridization will bring out the best traits in two genetically different parents, and inbreeding crosses two similar parents for offspring that also have the similar traits. Betta breeding can be rough no matter what, but it's important to get fish that are approximately the same size. This helps prevent injury to one of the fish. Looking at the size of each betta can ensure healthy spawn and a healthy breeding process for each fish.  Be aware that a fish that is too small may be too young to breed. Aim to breed bettas that are four to twelve months old, which can help ensure that the sizes are proportionate as well as help prevent bad quality spawn. Detect sexual maturity in your betta by looking for males that build bubble nests and females that have a whitish egg spot on their underside. Females are also able to build bubble nests - don't let that fool you. Many people want to selectively breed their bettas for fin size and finnage. Looking at the fins for characteristics you want to bring out as well as for potential injury can help ensure that you get the qualities you hope to breed.  Check the caudal, or tail, fin for straightness and curvature. Good breeding stock bettas with have straighter caudal fins that are curved in opposite directions. Avoid bettas with caudal fins curved in the same direction. Look for ray branching or splitting on all of the bettas fins. The more branches or splits you have, the more supportive, larger, and beautiful finnage you will get. Make sure the betta has no traces of fin rot, which looks like ripped or fuzzy fins with red tips or near the tears. Bettas come in and exhibit a wide range of colors on their bodies. Find the color bettas you like as mates or for your betta as a mate and try to choose colors that work well together.  Be aware that bettas come in colors such as red, orange, yellow, turquoise, steel blue or royal blue. They can also have black or iridescent features. For example, you might find that breeding the blues with black lace features give your fish beautiful colors.  Ask the breeder if you are unsure of what can work best for your betta.

Summary:
Buy bettas from one breeder. Choose your optimal betta pair. Check the size. Examine the fins. Combine complementary colors.