The three best ways of maximising the percentage of irrigation water that enters your garden soil are:

Eliminate under or over irrigation by checking the run-times for each of your irrigation zones. Remember that water applied at a rate faster than it can infiltrate into the soil can cause runoff and thus water wastage.
Set your irrigation timer to start irrigation early in the morning to reduce evaporation. Thus making more effective use of your water.
Avoid irrigating in windy conditions. Wind blows water droplets onto roadways and pathways instead of the soil. The least windy time of the day is very early morning.

By following these simple rules, your gardens are sure to be irrigated efficiently!