Formatting large amounts of data in Excel can be time-consuming if done manually. Here are some techniques to tackle it quickly and efficiently:

General Formatting Strategies:

1. Conditional Formatting:
- This is a powerful tool for applying formatting based on specific conditions in your data.
- For example, you can highlight cells that exceed a certain value, format negative numbers in red, or change the background color based on text criteria.
- Select your data range, go to the "Home" tab, and click "Conditional Formatting" to explore various formatting options and rules.

2. Styles and Cell Formatting Tools:
- Excel offers pre-designed styles that you can apply to your data with a single click.
- These styles often include font formatting, borders, and shading.
- Explore the "Styles" pane on the Home tab or use the various formatting options (font, alignment, borders, etc.) to create a consistent look for your data.

3. Format Painter:
- If you have a specific format you like and want to apply it to other cells, use the Format Painter tool.
- Click on the cell with the desired formatting, then click the Format Painter button on the Home tab.
- Now, click and drag over the cells you want to apply the same formatting to.

Formatting Techniques for Large Datasets:

1. Formatting by Table:
- Convert your data range into a table. This allows you to apply formatting to the entire table structure at once.
- Select your data range, then go to the "Insert" tab and click "Table."
- You can then customize the table style from the "Table Design" tab.

2. Flash Fill:
- This is a handy feature for automatically applying formatting patterns based on existing examples.
- Enter your desired format in a few initial cells, then select the entire range where you want to extend the formatting.
- Go to the "Home" tab and click "Flash Fill" in the Editing group.
- Excel will intelligently analyze your pattern and apply it to the remaining cells.

3. Format Painter with Filtering:
- Combine Format Painter with filtering to streamline formatting specific data groups.
- For instance, filter your data to show only a certain category.
- Apply the desired formatting using the Format Painter on a single cell within the filtered results.
- Excel will then apply that formatting to all the visible cells in the filtered group.

4. Macros (Advanced):
- If you deal with very large datasets regularly and have repetitive formatting tasks, consider creating a macro.
- Macros are a series of recorded steps that can be automated to save you significant time.
- However, creating macros requires some knowledge of VBA (Visual Basic for Applications).

Remember:

- Start with clean data: Ensure your data is well-organized and free of errors before applying formatting.
- Format as you go: If you're working with large datasets being imported, consider formatting while importing the data using tools like Power Query (if available in your Excel version).
- Test your formatting: Make sure your formatting rules don't cause unintended consequences before applying them to the entire dataset.

By using these techniques and planning your formatting strategy, you can significantly reduce the time it takes to format large amounts of data in Excel.