Make the subject line do actual work
"Update" or "Question" tells the reader nothing. "Budget approval needed by Friday" tells them exactly what to expect and how urgent it is before they even open the email — which affects whether it gets read promptly at all.
Put the ask in the first line, not the last
Busy readers often skim the first sentence and decide the rest later. If your actual request is buried in paragraph three, it may never be seen. State what you need clearly at the start: "I'm writing to ask for..." or "Could you confirm..." — then explain the context afterward, briefly.
Keep paragraphs short and use structure for anything with more than one part
A wall of text is harder to act on than the same information broken into short paragraphs or a simple bulleted list. If you're asking three things, number them — it's far more likely all three get answered than if they're buried in one paragraph.
Close with a specific next step
"Let me know your thoughts" is vague and easy to ignore. "Could you confirm by Thursday whether this works?" gives the reader a specific, small action to take, which is far more likely to actually get a reply.