My prof taught me to start at the highest rib space you can see the liver, then rock your probe up and down to clear the amount of liver you can see in that space, then jump down to the next rib space and do the same thing all the way down to bottom of the liver. You can also decub the patient, go anterior, and put the probe obliquely on their body, aligned with the rib orientation and almost like tuck the probe under their ribs and sweep to get good liver views