Press your lips together, add vocal cord vibration, then release.

Americans pronounce borrow as BAH-roh (/ˈbɑroʊ/). Stress falls on the first syllable — keep everything else short and quick. You'll hear it in sentences like "Could I possibly borrow a pen?".
Record yourself saying "borrow" and play it back. The mic stays on your device — nothing's uploaded.
2 syllables, 4 sounds. Tap a syllable to jump to its row, then explore each sound's mouth shape and how it's made.
Curl or bunch your tongue without letting the tip touch the roof of your mouth. Brace the sides of your tongue against your upper back teeth, and round your lips slightly.
Start with your mouth slightly open, then close your jaw slightly as your lips round. Shift your tongue back slightly, then stretch the back up.
The textbook way isn't wrong — it's just not how anyone actually says it.
Stress falls on the first syllable, not the others. Stretch BAH — keep everything else short and quick.