Within their territory, they will know all safe nooks and crannies, used for many resting times and getaways. This last point may be the easiest to arrange for your cat, but its importance should not be underestimated. Should she retreat to her hiding place, don't force her back out, but let her emerge on her own terms. This will also reinforce the trust between the two of you, as your cat will see you as neutral, not having contributed to her situation of fear, whereas you would by pulling her out of her hiding spot. The more hiding and semi-hiding spots you arrange for in your house, the calmer your cat will be, and she will feel the need to hide less frequently.
Cats living in a contemporary, barely furnished home are often nervous wreaks.
Considering your cat's natural behaviour, and designing a living space equally suited to human and feline inhabitants, goes a long way in promoting health and well being for your companion cat.