You should definitely include a cover letter when applying for a landman job. If you send an email to a hiring manager, I recommend using it as the body of your email. If you apply online through an applicant portal, upload it is an attachment if you are able to do so. The letter should explain the type of land work you excel in, as well as provide concrete examples of your accomplishments. You should also include why you want to work for that specific company and why you would be a good fit both for the company and the position. Address your letter to the hiring manager, or if you don’t know his/her name, address it to the company (don’t use “Dear Hiring Manager”). It should be tailored for the company/position, as opposed to just a generic form letter that you send out to everyone. I have found that oftentimes landmen don’t send cover letters (even when specifically requested), so by including one, you can demonstrate your professionalism and attention to detail, and stand out head and shoulders above the rest. Good luck on your job search!