A LMIA work visa can be applied only after receiving a valid job offer letter from any Canadian employer, who applies for LMIA, which means in the opinion of that employer there is no Canadian suitable for the applied job. Once the employer gets his positive LMIA, you will prepare all documents, like your job offer letter and your qualifications and then apply online for your LMIA work visa. Some common challenges are: the inability to find an employer that would be willing to go through the process of LMIA, possible delay in processing, and meeting the very minimum requirements for a visa. Proper planning and following through on these will definitely go a long way toward increasing your chances of being a successful candidate. Don't lose hope or give up. Be patient and follow up on your application for the best results.