Disclaimer: I am no expert at anything, except NOT being at expert at anything. These tips are just something that have helped me, or someone else, or could help me, or you. That's my goal. I'm not all about the telling you what to do. So take them as you will.
Communication is the key to everything in relationships. Whether it be a marriage, friendship, etc.
If someone sends you an email, text, FB message, etc. that requires a response, don't ignore it. I know sometimes we all forget to reply but it can be hurtful to the person who sent the message. Even if it's a small something to at least show you acknowledged it.
So take 2 seconds of your busy day to respond. You'll be glad you did.