"Eat that frog" is a productivity technique based on the idea that you should tackle your most important or challenging task first thing in the morning, rather than leaving them until later in the day when you may be less motivated or energetic.

"If it's your job to eat a frog, it's best to do it first thing in the morning. And if it's your job to eat two frogs, it's best to eat the biggest one first." - Mark Twain

The metaphor of "eating a frog" comes from the idea that if you had to eat a live frog, you would do it first thing in the morning to get it over with, rather than letting it sit there all day and cause you stress or anxiety. Similarly, by tackling your most difficult tasks first thing in the morning, you can get them out of the way and move on to other tasks with a sense of accomplishment and momentum.

To use the "eat that frog" technique, you can follow these steps:

1. Plan the day before - identify your most important or difficult task for you to complete the next day, this is the "frog" that you need to eat.
2. Make it your priority to complete it first thing in the morning, before you start working on anything else.
3. Set aside a specific time and place to work on the task and eliminate any distractions or interruptions, allowing you to achieve a "deep work" state.
4. Once you have completed the task, move on to your other tasks for the day, knowing that you have already accomplished your biggest and most important task.

As mentioned in Step 3, deep work occurs when you're able to focus without distraction on a cognitively demanding task. Deep work requires a high level of concentration and focus, and is often difficult to achieve in today's distractions-filled world, but it can be essential for productivity. Here are a few tips that can help:

- Set aside dedicated blocks of time for deep work in your calendar - this might be a couple of hours in the morning or a full day once a week.

- Reduce or eliminate distractions during deep work sessions - this might involve silencing your phone, closing unnecessary browser tabs, or working in a quiet location.

- Use productivity techniques like the Pomodoro Technique or the 2-minute rule to help you stay focused and avoid burnout.

The "eat that frog" technique can be a helpful way to stay focused and motivated, and to ensure that you are making progress on your most important tasks. However, it's important to be mindful of your own capacity and to take breaks and rest when needed.