Push a stream of air from your throat through your open mouth. No tongue or lip contact.

Americans pronounce herself as her-SEHLF (/hərˈsɛlf/). The L in "herself" is a dark L — the back of the tongue rises toward the soft palate, adding a small "uh" quality before the L. This is called the Dark L vs Light L, the kind of sound shift that makes everyday speech feel effortless. It comes out as her·SEHLF. Stress falls on the second syllable — keep everything else short and quick. You'll hear it in sentences like "She joined a crossfit box to challenge herself physically".
Record yourself saying "herself" and play it back. The mic stays on your device — nothing's uploaded.
2 syllables, 6 sounds. Tap a syllable to jump to its row, then explore each sound's mouth shape and how it's made.
Place your tongue tip near the roof of your mouth behind your top teeth. Push air through the narrow gap. No voicing.

Drop your jaw moderately. Touch the tongue tip behind the bottom front teeth and lift the mid-front part slightly toward the roof.

Keep the tongue tip down and pull the back of the tongue up toward the throat. The 'dark' sound comes from the back.

Lift your bottom lip to touch the very bottom of your top front teeth. Blow air through this contact point without voicing.

The textbook way isn't wrong — it's just not how anyone actually says it.
The L in "herself" is a dark L — the back of the tongue rises toward the soft palate, adding a small "uh" quality before the L. Dark L adds a small schwa-like "uh" before the L. The back of the tongue lifts toward the soft palate.
Stress falls on the second syllable, not the others. Stretch SEHLF — keep everything else short and quick.
Americans use a relaxed retroflex R — the tongue curls back rather than rolling. The R is one continuous sound with the vowel before it, not two separate sounds.