In this step, you need to understand the period you have chosen when planning to redecorate your period property and pick out the design styles current at the time and what their main features were.
At each period in history houses were built and decorated in different styles; rural and urban, expensive and cheap, contemporary and retro. There were sometimes competing aesthetics at the same time; for example Arts and Crafts versus Art Nouveau.
Is your home in a rural area, a rural town, a fashionable town or a city?
Would the occupants of your home have been farm or factory workers? Shop staff or clerical workers? Managers, land-owners or affluent company directors?
The fortunes of the same house may have changed; as urban centres spread, the middle classes have tended to build on the outskirts, handing their old homes on to less affluent people. This is seen in modern cities where the commercial centre of a city is often surrounded by the homes of poor people who need cheap access to employment but cannot afford to move to newer, better quality housing. Beyond this area is a ring of better houses, perhaps occupied by clerical workers. Managers choose to live further out still, often to the west in the UK so that the prevailing wind blows away the smoke and pollution from industrial areas to the east. Paradoxically, the cheap housing near the centre may then attract an artistic community; an area may become fashionable again and bring in young, wealthy people.
In styling your home, try to take the affluence of the earlier owners into account; a simple, rural home will be enhanced by a simple, unfussy look. Do not try to over-restore and over-decorate your house. On the other hand, a Georgian town house may have been the home of several poor families in the late 19th century but can now cope with a more affluent style.
Are you trying to recreate the glossy magazine view of your house, with only the fashions current at that point in time? Imagine the 'Ideal Home of 1875'. Who is your favourite architect or designer from that time? Take your ideas from advertisements, books and publications of the period.
The next step is to research your chosen period and style; get under its skin.