Toasted sesame oil has a strong aroma that can quickly dominate noodles or broth. It is useful precisely because a small amount makes an obvious difference.
Check whether your bottle is toasted or a milder untoasted oil, and follow the manufacturer's cooking guidance. In a simple noodle dressing, add a little near the end, taste, and stop while you can still distinguish the other ingredients.
Store as directed and keep the cap secure. If the oil smells unpleasantly stale, using more garlic will not restore it. Sesame also needs to be named when sharing food with someone who has an allergy; a tiny amount remains an ingredient. Do not describe a dish as free from sesame simply because the visible seeds were left off.