What is the best way to breed bettas and how long do they have to be together

I have 2 bettas (male and female) and i wanna breed them!

Be aware that this is an intensive thing, and involves time, effort, regular cleaning, culling (flushing) baby fish with defects, and having room to put everyone when they grow up.

Now that you're sure you want to do this and pay a heck of a lot of attention to the fish over the next few months, buy a tank that is at least AT LEAST five gallons. Bigger is better. No rocks in the tank, but a lot of plants. Also a styrofoam cut choped straight down in half when sitting on the counter helps as a place for the nest to be built if you secure it to the edge of the tank. Also, get some sort of clear tube open at both ends that is fish-safe.

Now go out and buy some more stuff. A microworm culture is great. Some vinager eels are good too. Maybe some small baby brine shrimp, too, but they are a bit more labor intensive. Get your cultures all nice and big and split them in half. Then grow them up again before you start breeding.

Now that you have food for the fry (baby fish) you can think about making them exist. Give the tank about six inches of treated, dechlorinated, lightly (aquarium) salted water, a heater and a filter that does not create a real big current. Don't forget all the plants. Let it sit for a few days, if not a week. In the mean time, feed Mrs. betta well, lots of bloodworms if you have them. Keep her in sight of the male, as well. When she's plump and has a little white dot poking out of her belly from between her fins then you can get down to business.