To ensure the best fit, it is advisable to take your measurements while wearing light clothing. For chest measurement, measure around the fullest part of your chest. For waist measurement, measure around the narrowest part of your waist. Length should be measured from the highest point of the shoulder down to the desired length. Sleeve length is measured from the shoulder seam to the wrist. If you are between sizes, it is generally recommended to choose the larger size for comfort.