An attractive resume template/outline makes it more powerful. Just as dressing smartly helps a candidate in an interview good formatting does the same for a resume. Looks do matter at all places in the real world and on paper. When you present yourself well you get noticed. Similarly when you present a good resume it will be noticed; otherwise it would be very easily find a bin to rest in.
There used to be a day when you could create one generic resume and then blast it to a wide range of jobs you were interested in applying to. Even if you are using a resume service this practice of blasting is generally frowned upon. HR professionals are inundated with resumes and they want to see that applicants have read the ad and are responding directly to it. One-for-all type of resumes are easily spotted and are generally discounted by HR. So work with a resume service to see how you can best tailor yours for each job you are applying to.
Make sure to have contact information on every page Nothing is worse than having an amazing resume and forgetting to add in contact information. Do not assume that if your resume is two pages that they will stay together either. Put your name and contact info at the top of every page and add in page numbers for a more professional look as well.
Focus on achievements Employers not only want to know what you have done in the past they also want to know where you have excelled. If you have awards achievements or on the job highlights make sure to add them. If you were part of a team you were part of the success. If your project increased production by 20% and you played a part in it add it on your resume!
No sample resumes are accessible. A competent resume writing service will provide a number of samples for review. You can assess the quality of their work only if have these samples. If there are no samples available on their website ask them for the specimens of their work. If they are unable to provide satisfactory examples of their work you had better opt for another service.