The technique

Sit as you would for any practice. Bring someone to mind, and silently repeat three or four phrases at a slow, unhurried pace. The traditional set:

Say them, pause, say them again. The pace should be roughly one phrase per out-breath, with room between. You are not visualising, affirming or persuading yourself of anything — you're repeating a wish and noticing what happens.

The five circles

When it feels false — and it will

Almost everybody hits this, usually in the first circle. You say "may I be well" and something in you answers you don't mean that. Three things help:

• You're not asserting a feeling, you're expressing a wish. "May I be well" is not the claim "I am well" or even "I like myself". It's closer to what you'd want for a stranger — which is all it has to be.
• If you can't start with yourself, don't. Begin with someone easy — a friend, a child, a dog. Slot yourself in later, when the phrases have some warmth in them.
• Resistance is information, not failure. Noticing that goodwill toward yourself feels absurd is arguably the single most useful thing this practice does.

Who it's for

If your obstacle is a harsh inner commentary — the voice that narrates your day critically — this is the technique to reach for, more than breath or body work. It's the one practice that addresses the tone of attention rather than its aim.

It's also the most-studied practice for shifting self-criticism and social warmth. Effects in trials are modest and real, which is the honest version of a claim you'll see stated far more grandly elsewhere.

Related

• Choosing a technique — by obstacle rather than philosophy.
• Guided recordings — several archives include metta practices.
• What to expect, honestly.

Sources

• Encyclopædia Britannica — Metta, for the tradition behind the phrases.
• NCCIH — Meditation and mindfulness.