I've previously advocated for feeder buses to run every half-hour during the off-peak. I'll flesh out that idea in this post.
IDEAL MINIMUM FREQUENCY STANDARDS
Peak - 6am to 10 am and 3pm to 7pm
Daytime - 5am to 9pm (7 days a week, excluding peak)
Evening - 10pm to 12 am (2am on Friday and Saturday nights/Saturday and Sunday mornings)
Early Morning - 4am to 5am
Night - 12am to 4am (2am to 4am on Friday and Saturday nights/Saturday and Sunday mornings)
Every 15 minutes during peak, 30 minutes during (the rest of the) daytime and 60 minutes during evenings and early mornings.
Every 7.5 minutes during peak, 15 minutes during (the rest of the) daytime, 30 minutes during evenings and early mornings, and 60 minutes at night.
As a result, all areas will get TUAG (every 15 minutes or more)service during the peak, and trunk routes (most main roads) will receive TUAG from 5am to 9pm, and some kind of service 24/7. This trunk service could be depended on, and would make it possible to live comfortably in many parts of Perth without a car.
More important corridors should get more frequent service, but preferably in the above ratio.
For example -
Every 3.75 minutes during peak, 7.5 minutes during (the rest of the) daytime, 15 minutes during evenings and early mornings, and 30 minutes at night.