Macrium offers to build you a bootable "Rescue Media".  It has a wizard that automatically downloads all necessary Windows PE components (WinPE - Pre-installation Environment) from Microsoft and builds it locally on your target media for you.  A no-brainer... 
 
If you wish you can use it as an offline backup tool, as it contains a copy of Macrium Reflect running on PE.  You will definitely need it for a restore.

For an experienced user disconnecting other drives usually isn't needed.  For a novice it may be better to disconnect them to be on the safe side.
 
+1 for Macrium Reflect.  This coming from an ex-Acronis True Image user.
The last Acronis version I had was 2013, but the Macrium "user friendly" procedure to create the WinPE rescue disc is much better than the "user unfriendly" procedure that was in the last Acronis version I had.  Acronis used to also have a Linux rescue disc version but I never got that to work correctly.
 
 

I had a few fail to restore issues with Acronis.
That's when I switched to Macrium.

Steve_Karl
I had a few fail to restore issues with Acronis.
That's when I switched to Macrium.

ouch! good to know

While some of us are bashing Acronis, it failed me twice.  Didn't get a potential 3rd chance and when I switched to Macrium Reflect.