A new update to Google Assistant will allow you to put your routine shortcuts on your homescreen. According to 9to5Google, the feature is rolling out to more users. The option "Add Routines to your Home screen" will appear when you edit any routine. There will be a small pop-up that will show up when it happens for the first time.
The move seems like a way to appease any complaints from Google moving the ability to trigger routines from the primary set of action buttons in the Home app to a more extensive menu. That redesign made it more troublesome to access these features. But with this new option, it will be much easier to get to the routines you need.