Place your tongue tip near the roof of your mouth behind your top teeth. Push air through the narrow gap. No voicing.

Americans pronounce surfboard as SURF-bord (/ˈsɜrfˌbɔrd/). Stress falls on the first syllable — keep everything else short and quick. You'll hear it in sentences like "The surfboard was waxed to provide traction".
Record yourself saying "surfboard" 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.

Flare your lips and push them away from the face. Lift the middle of your tongue toward the roof of the mouth.

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

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

Start with the 'aw' jaw drop and rounded lips. Pull the tongue back and up while keeping the lips rounded for the R.
Touch the tip of your tongue to the roof of your mouth just behind your teeth. Add vocal cord vibration as you release.

The textbook way isn't wrong — it's just not how anyone actually says it.
In "surfboard", the "d" is not released — the articulators get into position but hold without the burst of air. Air stops but there's no release burst — the articulators hold position.
Stress falls on the first syllable, not the others. Stretch SURF — 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.