You're staring at a to-do list that seems endless. You know you need to start making some progress, but you have no idea where to even begin. How can you effectively prioritize when everything on your list seems like a priority?

Chances are, you just need to take a step back, refocus, and return to that overwhelming to-do list with a fresh perspective.

Take a minute to ask yourself these three key questions to figure out what actually needs to be tackled first.

1. Does this absolutely need to be done today?

I've mentioned before that a surefire way to filter through your to-do list is to focus on only the items that need to be done that very day.

So, when dealing with a roster of tasks that seems insurmountable, start here. Zone in on each item and determine whether or not it's urgent enough to earn a spot on today's list.

If not? Save it for tomorrow or later in the week. Right now your goal is to separate the wheat from the chaff and streamline your workload for the day.

2. Does this need to be done by me?

Now, with the items you have left on your list, it's time to ask whether or not this is truly something you need to handle personally.

Is this a task that would be better off handed to an assistant, a subordinate, or perhaps a colleague who's better equipped to handle it? Or, even further, is this a mindless task that could be automated entirely?

If there's anything that can be shuffled off your plate and onto someone else's, go ahead and do that (politely, of course!). Just be prepared to return the favor when that person is spread too thin.

3. Does this need to be done at all?

At first glance, this seems stupid. Why would you have something on your to-do list that doesn't actually need to get done? But, it's easy for all of us to fall into the trap of continuing to do things simply because we've always done them.

For example, at a previous job, I spent an hour each month filling in a spreadsheet that I later found out nobody ever looked at. It was just one of those tasks that had always been completed by the person in that position -- regardless of the fact that it didn't really matter.

This is why you need to turn a critical eye to the items left on your own to-do list. Do you really need to clean through your inbox today, or is that just something you always do on Wednesdays? Do you actually need to attend that weekly meeting, or could they survive without you for this week until you're caught up on work?

There won't always be something you can eliminate from your to-do list entirely. But, if you spot an opportunity, go ahead and do so. It'll instantly make you feel less frazzled.

Everybody knows that an overwhelming to-do list can be stressful -- not to mention difficult to prioritize. Rely on these three questions, and you'll wind up with a slimmed down list of the most urgent items that you can start chipping away at.