How can I make sure I'm ordering the right size?

Measuring Guide

We strongly recommend having your measurements taken by a professional tailor or seamstress or having someone help you, measuring by yourself will cause inaccurate measurement results and subsequent disappointing issues. Measurements should be taken in the undergarments you plan to wear under your dress. Make sure to keep the measuring tape comfortably loose, like you'd want your dress to fit.

Keeping a thumb in the inside of the tape is a practical way.

Bust Measurement Standing up straight with your heels together, put your arms at your sides and relaxed. Measure the fullest part of your chest and around your back. Pay attention to that this is NOT your bra size. You must wear a bra while taking the measurement.
Waist Measurement Measure the narrowest part of your torso. Practically, it is usually an inch or so above your belly button.
Hips Measurement Standing up straight with your heels together, measure around the fullest part of your hips. Find your hip bones and measure there. Usually it is approximately 7 inches below the natural waistline.
Hollow to Floor Measurement Standing up straight with heels together, measure from the center of the collarbone (Hollow) straight down to your feet. Attention please: you should measure it barefoot.
Height Measurement Standing up straight with heels together, measure from the top of your head straight down to your feet. Attention please: you should measure it barefoot.