Earn a girl's trust: 5 simple tips.
1.Keep promises and act responsibly.
Be punctual, never be more than 10 minutes late, and try to always keep your word to a girl or other person.

2. Talk carefully about other women you know.
If you have female friends that you want to introduce your significant other to, or want to show that a girl can trust you, then never compliment your girlfriends' looks.

3. Answer important questions honestly, but use harmless lies when appropriate. Your big deceit will breed suspicion and distrust, which sometimes cannot be corrected. One such incident can destroy your relationship.
4. Be polite online and on the phone.
5. Protect your girlfriend in front of other people. If someone teases her, then take the side of the girl. A girl should know that she can always count on her boyfriend's support.