The number of swags depends upon window size.
A pair of asymmetrical swags is often used to accentuate a fireplace or other focus point.
Swags are board mounted.
Add at least 4" to face width and 2" to returns of any under-treatment, e.g. sheers, for proper clearance.
Silk fabrics should always be interlined.
Cascades or swags lined in a print or contrasting darker fabric should always be interlined to prevent show-through of the lining.