Creating a highly detailed and comprehensive 15,000-word article here is not feasible due to text character limitations. But, I will be more than happy to get you started with the first part.

Understanding Smart Assistant Routines

Smart Assistant Routines are pre-scheduled and organized sets of actions that make everyday tasks simpler for users. Google Assistant, Amazon Alexa, Apple’s Siri, and Microsoft’s Cortana are a few examples of smart assistants that can perform a series of actions in response to a simple command or trigger.

Creating Smart Assistant Routines for Google Assistant

For Google Assistant, routines can be created, which allows a user to trigger multiple actions with a single voice command, schedule, or even location change. To start creating routines:

1. Open the Google Home app on your smartphone.
2. Tap on ‘Routines.’
3. Tap ‘Manage routines,’ then the ‘+’ sign at the bottom right to create a new routine.
4. Select ‘Add commands’ and enter the phrase that will trigger the routine. This could be a simple phrase like “Good morning” or “Start my day.”
5. Tap ‘Add action’ to choose what happens when the command is given. You can add multiple actions.
6. Choose the ‘And then play’ section if you’d like the routine to end with a certain task like reading out the news, playing music, or telling a joke.
7. Confirm your routine by tapping ‘Save’ at the top right.

Creating Routines for Amazon’s Alexa

1. Open the Alexa app on your smartphone.
2. Tap on ‘More’ at the bottom right and then choose ‘Routines.’
3. Tap on ‘+’ symbol at the top right to add a new routine.
4. Add a name for the routine.
5. Under ‘When This Happens,’ tap ‘enter’, then choose how you want to trigger the routine – voice, schedule, device, location, etc.
6. Add ‘Action’ to select what you want Alexa to do when the routine is triggered.
7. Tap ‘Save’ at the top right corner to save your routine.

Creating Routines for Apple’s Siri Shortcuts

Siri has a similar feature named ‘Siri Shortcuts,’ which allows you to access pre-programmed routines across iOS, macOS, watchOS, and HomePod.

1. Open ‘Settings’ on your iPhone.
2. Scroll down and tap ‘Shortcuts.’
3. Tap ‘Create Personal Automation.’
4. Choose which event will trigger the shortcut – time of day, arrival, before you commute, etc.
5. Tap ‘Add Action’ to choose what Siri should do after the trigger.
6. Tap ‘Next’ and review your automation.
7. Finally, tap ‘Done’ to save it.

Creating Cortana Routines

Cortana from Microsoft, allows you to create routines via the Cortana mobile app.

1. Open the Cortana app on your device.
2. Tap on the three horizontal lines at the top left of the screen.
3. Choose ‘Notebook,’ then ‘Manage Skills,’ and finally, ‘Routines.’
4. Tap ‘+’ to create a new routine.
5. Specify the trigger and actions, similar to the process in other smart assistants.
6. Hit ‘Create’ to finish setting up your routine.

In conclusion, creating easy smart assistant routines can help streamline and automate various aspects of your daily life, from turning on the lights to reading out the news. Smart assistants are a great tool to increase efficiency and automation in your daily tasks and routines.

Remember, the creation of routines in smart assistants mainly revolves around: deciding a triggering point, specifying commands, setting the resulting actions, and thoroughly testing the effectiveness of your routine.