I was always looking to start a navigation using Google Maps on Android with a just a single click. Of course you can set some presets or even a location, and since a few generations of Google now, there is even a navigation shortcut for your work or home address. But one thing, all these methods were missing: A real one click solution. Every shortcut only gets you to the calculated route, you always have to start the real navigation with another click.
Using tasker, I found a way to finally realize what i needed.
Tasker has support for intents and using the Google Maps-Intent works like a charm.
Create a new task.
Add System -> Send Intent
Action: android.intent.action.VIEW
Type: None
Data: google.navigation:q=location+you+look+for&mode=w
modes:
d
for car (drive)w
for walkb
for bike
Take a look the the manual page for all options.