When I'm using tail -f and I want to return to the shell, I always use CTRL+C. Or when I am typing a command and feel like aborting it and starting over, I simply CTRL+C to get back to an empty command line prompt. Is this considered bad practice? I sometimes feel there might be a better way to break away from something, but really have no idea. 
Is CTRL+C incorrect to use to return to command line?
linux;bash
Ctrl+C sends a SIGINT to the program. This tells the program that you want to interrupt (and end) it's process. Most programs correctly catch this and cleanly exit. So, yes, this is a correct way to end most programs.There are other keyboard shortcuts for sending other signals to programs, but this is the most common.