There are many things you can do to help you hold the phone and your head steady and get a good result.
For maximum stability, we recommend holding the phone in both your hands and resting your arms on a table whilst seated. You can also rest your elbows on the arms of a chair, rest the phone in a holder or cradle on a table, or hold the phone against a wall whilst completing the tests. Give these suggestions a go and find the method that is most comfortable for you.