If a plant does not look wilted or stressed during the hot afternoon, it probably does not require water. Plants that are still wilted or stressed early in the morning deserve priority if you water. Look to see how plants that you have in your yard are doing in other landscapes, particularly in landscapes that are not being watered at all. Plants that are coping well with little or no watering elsewhere are the best candidates for water cut back in your yard. Don't be fooled by plants that simply look like they are dying but really are not.
Some plants can cope with drought by going into some degree of dormancy.
All the typical lawn grasses in our area can do this. Daylilies and liriope are examples. Categorize your Plants. Rank your plants and plant groupings as to their relative need for water in order to survive. Plant vary as to how fast they become resistant to drought after planting.