I feel the biggest productivity hack is to completely understand the tool which you are using on day to day basis.
I am working in the software industry for the last 10 years and I found people don’t use their IDE ( code editor ) with its full capabilities where they are spending 6-7 hours per day.
If you know the shortcuts and hacks then your productivity increases by 10x.
The whole idea is to save time using the tool if it is consuming time then you should figure out the right way to use a tool or change the tool.
I personally go into detail with tools with all the shortcuts and functionality. Having good UX and keyboard shortcuts is more important than good UI for me.