Start with a polite salutation:  Make sure to address your employer/manager respectfully, use their name for professionalism.

State your intention clearly:  Mark your last working day and decision to resign clearly.

Show gratitude:  Showcase appreciation for the openings, experiences, and skills you have gained from the company.

Keep it concise:  Do not include excess details and make sure to have a professional tone throughout the letter.

Optional reason:  It is not necessary to mention your reason for resigning but if you include it make sure to keep it brief.

Offer to assist:  Include your willingness to help with anything over the transition period to have a smooth handover.

Provide contact information:  Include your professional email or phone number in case the employer wants to contact you in future.

Avoid negativity:  Do not include any airing grievances or unprofessional comments in the resignation letter.