Useless phrase: We're overthinking this.
Why it's useless: You're not offering a solution or a way to proceed. You're complaining.
Useful variation: Let's simplify this by going with X.
Useless phrase: Just get it done.
Why it's useless: Again, not a solution. A demand, and probably a silly one at that. There is an exception for this one where the non-doer is really an employee who spends more hours in a day on excuses than on actual work.
Useful variation: What are the barriers to doing X? Here's how we're going to work around each of them.
I'm on a mission to expunge useless phrases from my vocabulary. What other useless phrases do you know?