@Sophia2017,
I use the Scott Smith’s low impact spray approach. You can find lot of good info under the Guide category.
Low-Impact Spray Schedule (2019 Edition) - #58 by scottfsmith.
Please read label (on the internet) before even making purchases of chemicals. Avaunt and Imidan are not to be used in residential settings, only commercial orchards.
Two abbreviations that you should know are REI, a Re-entry interval ( when you can re-enter your orchard/garden after spraying), and PHI, a pre-harvest interval (when you can harvest your fruit after spraying). This is to minimze risks to your health.
Re. Spraying, when to spray is as important as what to spray. Using the right material at a wrong time will not get you a result you want.
In my experience, low impact spraying is often more expensive, time consuming and not as effective.