Coneflowers love the sun, are drought tolerant, attract beneficial pollinators, and look awesome while doing it! The worst planting mistake you can make with a coneflower is to plant the root crown below the grade of the soil. This can cause the coneflower crown to rot.
To propagate coneflower you can divide when they are large enough, take basal stem cuttings, or plant from seed. Seeds benefit from stratification. Generally when I plant from seed I just spread them out in the garden where I want them to grow then let nature take its course. To learn how to separate the coneflower seeds watch this video I put together.
Unfortunately there is one major disease that coneflowers can get called Aster Yellows. Aster Yellows isn't pretty. It's best to remove all infected plant material from the garden - do not compost.