How to create a Service in macOS to make life easy!

Scenario, you want a keyboard shortcut always available to say send a new email using the mail app, or say to eject a hard drive.

Say welcome to Automator app bundled with all macOS, kinda has always been. Open Automator app, select New, from options choose Service. On top under Service receives selected hit "no input" to make it available in all contexts. Then add the option in workflow window. 

Say for New mail option:
1. Under actions search box, type "mail". 
2. Then double click "New Mail Message". Of course this requires you to have setup the Mail app as your email client. But if you use Outlook, this can be setup as well. 
3. Anyway hit save. 
4. Then head to System Preferences app and under keyboard>Shortcuts>General find the service you just created! Click the right side of the screen and add your keyboard shortcut!

For my second example, the create a service to eject a HDD:
1. At step 1 above, type Get Specified Finder items to create the new sub-window
2. Drag and drop HDD partitions into the above space
3. Then from Actions search box, type Eject
4. Save and repeat actions in #4 above with a different shortcut

Instead of Services, you can also create Applications in Automator and drop them in Utilities folder. Then place aliases on the Desktop or in the Dock.

Hope this is helpful to the motivated and keyboard shortcut lovers!