This section is from the book "The Florists' Manual", by William Scott. Also available from Amazon: The Florist's Manual.
There are quite a number of climbing or vine-like habit of plants that are useful for this purpose. Many that would be useless to use in vases make pretty basket plants because in the vase they are exposed to drought, sun, wind and neglect, while the basket has more or less shelter and is under the care of some one whose duty it is to keep it well supplied with water, the chief need of a successful hanging basket. The soil in the basket should be rich and daily it should be taken down and dipped in a tub of water or thoroughly soaked with the hose, but never left sitting in a foot of water for half an hour, as 1 have seen, for that will drown the plants.
A good selection can be made from the following. The upright or center plants can be a selection of zonal geraniums, fuchsias, coleus, achyranthes, petunias, but a free flowering, compact growing zonal geranium is best of all. The climbing and drooping plants can be chosen from nasturtium, lobelia, thun-bergia, Nierembergia gracilis, senecio, Kenilworth ivy, ivy geranium, Pilogyne suavis, Abutilon vexillarium, maurandia, double sweet alyssum, glechoma, money vine, saxifraga.
What constitutes a good basket is the profusion of drooping plants that hide the material that forms the basket, whether it be a frame of wire lined with green moss or earthenware.