I spent almost half my life deaf (41 yrs old now). 2 years ago I regained my hearing with a cochlear implant. Here are some tips and techniques to make communication a little easier.
Remember, even with mild hearing loss visual communication will aid their ability to understand you. Make sure they can see you before you speak to them.
Speak clearly but naturally. Over exaggerating your speech often causes you to not use natural visual communication such as facial expressions, body langue and hand gestures. Clearly but naturally.
Never yell at them. A little extra volume might help some people but never yell. Because they are using visual communication and if you LOOK like you're yelling on your face they'll assume you are.
Don't have anything in your mouth such as gum or a cigarette. Also don't cover your mouth or face.
Sunglasses can sometime impair communication because we use our eyes to communicate too. If they seem to be impairing their ability to understand you. Try taking them off.
Be conscious of any bright light behind you that's shining in their eyes and making it difficult to see you.
Use any hand gestures, body langue or mime things out that'll help you communicate a key word or point when needed. Exp. mime driving a car if talking about driving somewhere.
Don't be afraid to write it down if they're having a hard time understanding. Or make use of your phones notes. Usually just a key word or two is all that's needed.
Rephrase it. Sometimes a combination of words are hard to understand. Try to rephrase it. Exp: "can you move your car for me" to "move your car please".
Never roll your eyes or say something like, "never mind it's not important". They can't control the situation and it's just rude.
Lip reading is hard work. Can be very frustrating at times. Imagine playing wheel or fortune 24/7. You constantly have to fill in the missing pieces and a headache will come without a break or two.
Everyone, even you, look away or to the side when you're concentrating on something. If you ask a question and they look away to puzzle it out. They're not ignoring you. Give them a moment to find it.
Learn the asl alphabet. You don't need the entire language but if you can finger spell key words you won't have to write or type them. Plus, it's a fun language.
Overall. Speak to them with respect. Face to face and clearly. That alone is a big help. And of course you can always ask them how you can make communication easier.