Fit, stretch and closures
Measure the relevant body area and check which parts can adjust.
Compare the fit chart for that garment
Use the manufacturer’s directions and compare the actual measurements with the chart for the selected option. Gloves and stockings may use different measurements from dresses. A one-size label gives no usable range by itself.
Find where the garment opens
A zipper, strap or lacing can change how the item goes on. Decorative lacing may give little adjustment. Confirm where the closure is and what it changes if a listing does not explain it.
Leave room for layers
Measure with the layer you plan to wear underneath when the brand’s instructions allow it. A fitted harness and a full garment can need different amounts of room.