Construction techniques can assist you in dating furniture. In the 17th Century, butt and rabbet joints were used. It's easy to spot an antique by the drawers, because joints weren't machine-cut until about 1860.
To determine age, consider the form and function, tool marks, construction techniques, and materials used in the furniture. Pit saws, used from roughly the 1600s to 1750, left irregular, slanted, deep rough marks.Use your fingers on drawer bottoms or backboards of case furniture.If you can feel slight, parallel ridges and hollows, the piece was hand planed, probably prior to the mid-19th Century.Many vintage furniture buyers opt for quality reproductions that are more affordable, and either option is fine providing that you research your subject well when identifying antique furniture.There is no exact science where antique furniture is concerned; you simply make an educated decision based on what is most important to you.