Test the fit of your motorcycle jacket by sitting in your riding position for several minutes, wearing typical clothes underneath. It should be snug at the wrists and across the arms. Make sure it covers your hips, unless you’re buying a suit that zips together. Baggy gear will leak warm air in cold weather and expose your skin in a crash.
For women: don’t compromise on fit. A men’s cut that leaves gaps around the hips or shoulders won’t protect you properly. Rider forums and women’s groups are great for finding gear that fits right.