How to be a better LGBTQ ally:

• Be a listener.
• Be open-minded.
• Be willing to talk.
• Be inclusive and invite LGBT friends to hang out with your friends and family.
• Don't assume that all your friends and co-workers are straight. Someone close to you could be looking for support in their coming-out process. Not making assumptions will give them the space they need.
• Anti-LGBT comments and jokes are harmful. Let your friends, family and co-workers know that you find them offensive.
• Confront your own prejudices and bias, even if it is uncomfortable to do so.
• Defend your LGBT friends against discrimination.
• Believe that all people, regardless of gender identity and sexual orientation, should be treated with dignity and respect.

Be a better trans ally:

• Don't make assumptions about a transgender person's sexual orientation. Gender identity is different than sexual orientation. Sexual orientation is about who we're attracted to. Gender identity is about our own personal sense of being a man or a woman, or neither of those binary genders. Transgender people can be gay, lesbian, bisexual, or straight.
• If you don't know what pronouns to use, listen first. If you're unsure which pronoun a person uses, listen to the pronoun other people use when referring to them. If you accidentally use the wrong pronoun, apologize quickly and sincerely, then move on. The bigger deal you make out of the situation, the more uncomfortable it is for everyone.
• Don't ask a transgender person what their "real name" is. Respect the name a transgender person is currently using.  
• Be careful about confidentiality, disclosure, and "outing." Some transgender people feel comfortable disclosing their gender history, and some do not. You should never share this information, speculate, or gossip about a person you know or think is transgender. Not only is this an invasion of privacy, it also can have negative consequences in a world that is very intolerant of gender diversity. 
• Respect the terminology a transgender person uses to describe their identity. Respect the term (transgender, transsexual, non-binary, genderqueer, etc.) a person uses to describe themselves.
• Be patient with a person who is exploring their gender identity. A person who is questioning or exploring their gender identity may take some time to figure out what's true for them. For example, they might use a name or pronoun and then decide to change the name or pronoun again. Be respectful and use the name and pronoun requested. 
• Understand there is no "right" or "wrong" way to transition. Some transgender people access medical care like hormones and surgeries as part of their transition, and others want their authentic gender identity to be recognized without hormones or surgery. Some cannot access hormones and/or surgeries due to a lack of financial resources or access to healthcare. A transgender person's identity is not dependent on medical procedures or their physicality. Accept that if someone tells you they are transgender, they are.
• Don't ask about a transgender person's genitals, surgical status, or sex life. It would be inappropriate to ask a cisgender person about any of these things, and it is equally inappropriate to ask a transgender person those questions.  
• Avoid backhanded compliments and "helpful" tips.While you may intend to be supportive, comments like "I would have never known you were transgender — you look so pretty," "He's so hot. I'd date him even though he's transgender," or "You're so brave" can be hurtful and insulting. 
• Challenge anti-transgender remarks or jokes. You may hear anti-transgender comments from anti-LGBTQ activists, but you may also hear them from LGB people. It's important to challenge anti-transgender remarks or jokes whenever they're said and no matter who says them.
• Support all-gender public restrooms. Some transgender and gender non-conforming people may not feel like they match the signs on the restroom door. Encourage schools, businesses, and agencies to have single user, unisex and/or all-gender restroom options. Make it clear that transgender and gender non-conforming people are welcome to use whichever restroom they feel comfortable using.
• Set an inclusive tone. In a group setting, identify people by articles of clothing instead of using gendered language. For example, the "person in the blue shirt," instead of the "woman in the front." Similarly, "Sir" and "Madam" are best avoided.  
• Know your own limits as an ally. Don't be afraid to admit when you don't know something. It is better to admit you don't know something than to make assumptions or say something that may be incorrect or hurtful. Seek out the appropriate resources that will help you learn more. 

Source: GLAAD