The golden rule is good to remember no matter what career you happen to be in.

I feel this very important. It's easy to disregard someone's work just because they made a mistake. It's important though to remember that all humans make mistakes even simple ones. The right thing to do would be to politely correct them but still acknowledge their work or message.

A good tip to make your email formatting more professional is to make sure you create a hyperlink. A hyperlink will make your email look less cluttered than a copying and pasting a normal URL.

If setting up a meeting with someone to deliver any bad news or anything that will be emotionally heavy don't cause any unnecessary worries. By this I mean don't say something like "Hey can we meet...I have some news you might not like". This may cause the recipient unnecessary anxiety and emotional trouble.

When sending an email with an attachment be sure to check what the name of the attachment is. For example, if you name a document like "paperwork123" this might come off as unprofessional to some.

There have been instances where people will answer emails outside of their normal business hours, but this can be problematic. Some people might misinterpret you trying to keep up with your emails as you trying to "one up" everyone by always be available. It's good to have time for yourself outside of work even if it is something as simple as writing an email.