Highlight your text and click Format → Font. Clear out the ‘Size’ field and enter a slightly smaller number. You can use decimals to fine tune your font size.
Highlight your text and click Format → Font → Character spacing. In the ‘Spacing’ drop-down menu, click ‘Condensed’ and adjust the space between letters using the arrows on the right. Anything greater than 0.3 pt is too tight.
Highlight your text and click Format → Paragraph. In the ‘Line spacing’ drop-down menu, click ‘Exactly’ and, in the ‘At’ box, enter a number no less than one full point below the original font size. Remember, you can use decimals.
When scrunching, never forget about readability or uniformity. Don’t scrunch any more than necessary, and whatever you do, do it throughout the document.