All costume periods have a distinct silhouette, or outline. Things to look for are the neckline, waistline, and hem, as well as sleeves for women. For men, look for shoulders, waist, leg/pants. Accessories can also really define a period.
Costume History What the heck period is that?
The SilhouetteWomen Men Neckline Shoulders Waistline Waist Sleeves Leg/pants Hem
Gothic WomenHigh, round necklineHigh waistLong sleevesLong Hem
Gothic MenBroad shouldersLong sleevesFull hem Short Long
Early RenaissanceEarly 1500sMid - high neckline Oval Square V-neckNatural WaistLong sleevesLong, full hem
Early RenaissanceBroad shouldersLong sleevesFull hem Short Long
Mid RenaissanceBroad shouldersLong sleevesPumpkin Hose or fullhem