Good sterile seed starting soil. Keep it moist but not soaking wet, warm with a heat mat and use plenty of light. The seedlings will sprout more reliably if they are fresh. For every year after the seeds have been collected, you lose about 30% of them to age and dehydration. Seeds older than 5 or so years will not usually sprout, or you may get one or two out of fifty. The photo shows the flower stalks and they should be pinched off to encourage more side leaf growth. See my other other recent posts about the proper seed starting mixes. NEVER use soil from a garden to start new seedlings.

I've direct sowed holy basil into my vegetable garden for 3 years now with great success. Given the number of young plants that sprout, I have very high germination rates. I also direct sow thai and other types of basil as well with good success. While indoor starts can give you a jump on the season, direct sow some as well to spread out your harvest window.

FataMorgana

Basils are warm weather crop.
Starting from seeds will take months. I have done that.
But I stil plant seeds too.
To get a head start buy a bunch from supermarket (Korean/ oriental) put them in water and let them root. Then plant them. Later, also use cutting of your plant, put them in water, place them in shade. When they root, plant them.
One note: pinch off all leave except three or four on top.

Try Tie basils. They are very flavorful and have a pinkish color.
One thing about basils is that it is only good fresh. That is , they loos aroma when dried. Same goes for cilantro, parsley and taragon.

All my basil seeds germinate in less than 2 weeks. I start them indoors with heat mats under the trays of pots. Cilantro once dried has almost no flavor at all. I don't even bother to dry it or use any dried in any recipes.

Not all basils are created equal...

Sacred Basil or tulsi still has flavor when dried - it is very different from the basils you find in the produce department of your local supermarket. Tulsi is sometimes used in herbal teas. In fact there is a whole line of tulsi tea commercially available. I think the company that puts it out is called "Simply India." Pretty tasty.

I also find that the thai basil (I usually grow "Siam Queen") also retains flavor when dry. Not as much as the fresh but the thai basil I dried last season came in handy when I made pho (vietnamese noodle soup) during the winter. Thai basil is a necessary component - it wouldn't taste right without it. It is not something that I can readily find even in the specialty shops so I have to grow my own.

Other basils, use them fresh or freeze for use in pestos and other dishes. Dried really isn't the same.

FataMorgana

Ya'll, I slapped one nursery purcased basil into my garden and because I didn't know better let it go to flower and seed. That sucker kept coming back for two years, even in my compost pile! I would suggest starting it in place in warm weather and cutting off the flowers...my wife loves pesto but I don't love weeding!