If you have seen the person do something like make a speech or win an award, a brief mention or congratulation gives a personified touch to your email, increasing the effectiveness of the task or inquiry.

• Spell Check and proofread your email for common typing errors and spelling mistakes.
• Don't say 'Please ignore/excuse Typos' as it only sends the message that you don't care.

Check for the attachment that you mentioned in the email.

"When you start with the word “I,” it sends a message that you are more important than the person that you’re communicating with,” 

Jonathan Tisch

CEO - Loews Hotels

Do not exaggerate or say things that are not true. You can simply ask for clarification, without stating anything fictitious.

• Often we misrepresent ourselves with an unintended tone.
• Reread your email for tonal accuracy and politeness.
• Don't use the word 'you' too much.

If there is something new or worthwhile happening in your life, like an incoming trip, or an article you wrote, you could update to the recipient. If they happen to have an opportunity, the news you share helps them recall you better.

• In an email which has an event or plan, we need to give sufficient and concise information.
• Answer the five Ws: Who, What, When, Where, and Why, as applicable.
• This reduces the clutter of back and forth emails, and you respect the time of the recipient.