Your first day with a new strength is a test. Vape a few puffs and wait a few minutes. Are you satisfied? Do you feel any dizziness or nausea? That's a sign you're getting too much nicotine. Step down a level. If you're still craving a cigarette after 10 minutes, you might need a bump up.

Also, pay attention to your device. A high-powered sub-ohm mod produces more vapor per puff, so you get more nicotine per hit than from a small pod. If you're using a powerful device, you often need a lower strength than you'd use in a pod.