Assign hotkeys to everything.
With just a single keystroke I can instantly initiate or switch to all my apps
I have arranged the hotkeys in a logical order and after some time I don't even have to think about them it just becomes automatic muscle memory.

I run
up to 3 instances of my file commander utility
up to 9 instances of a Windows 7 command prompt
up to 8 instances of my programming editor

So typing ctrl-alt-f starts or switches to already running instance "F" of my file commander
ctrl-alt-g and ctrl-alt-h are for instances "G" and "H"

ctrl-alt-1 ctrl-alt-2 thru ctrl-alt-9 are for the 9 command prompts

ctrl-alt-j ctrl-alt-k and 6 more are for my editor

I can start or switch to a desired app instantly. It would take longer just to move my hand to the mouse.

How one chooses to work is a personal preference. I have used this system since the last millennium... I love it

What about for apps like Word and Excel? See AutoHotKey
and/or
alt-tab for those occasions.