Press your lips together. Air flows through your nose. Vocal cords vibrate.

Americans pronounce mare as MAIR (/mɛr/). You'll hear it in sentences like "Compare the hare with the rare mare" or "Where is the bear that scared the mare?" — more examples below.
Record yourself saying "mare" and play it back. The mic stays on your device — nothing's uploaded.
1 syllable, 2 sounds. Explore each sound's mouth shape and how it's made.
The textbook way isn't wrong — it's just not how anyone actually says it.
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.