Although this method tends to be less effective, you could choose to reach out to a company directly even if they have no current job postings. You could either call directly or send an email inquiring about any possible positions they may have.
As email continues to become a common form of communication, this tends to be the more appropriate option. In your email, share a little bit about yourself and why you are interested in their company. Attach an updated version of your resume and a link to your portfolio, if applicable.