1)
Specify what your job opening is about. Job description has to give job seeker good idea about what he/she will have to do.
Good examples:
Registered nurse,
Software developer.
Bad examples: "Work at home" and "Contact us to find out what the job is about".
2)
Include keywords that would help job seeker find your job posting.
See
examples of the most popular job search keywords here.
3)
Avoid duplicates. Job seekers don't like to see lots of duplicates of the same job opening. Job search sites delete or hide such duplicates.
If you have more than one job opening -- go ahead and post all of them, but please don't post duplicates.
See also:
How to avoid duplicates with multiple locations jobs.
4)
Don't ask for money from job seekers. You have to pay your employees, not the other way around.
If you're asking for money directly or indirectly -- you are not offering job, you are selling something.
Please go someplace else with such offering.
See also:
To Post or Not To Post?