Submit your research articles to open access journals, when there are appropriate open access journals in your field.
Deposit your preprints in an open access, OAI-compliant repository. It could be a disciplinary or institutional repository. If you have questions about archiving your eprints, then see Stevan Harnad’s Self-Archiving FAQ.
Deposit your postprints in an open access repository. The “postprint” is the version accepted by the peer-review process of a journal, often after some revision. If you transferred copyright to your publisher, then postprint archiving requires the journal’s permission. However, many journals have already consented in advance to postprint archiving by authors. Some will consent when asked. Some will not consent. For publisher policies about copyright and author archiving, see the searchable database maintained by Project SHERPA. If you have not yet transferred copyright to a publisher, then ask to retain copyright. If the journal does not let you retain copyright, then ask at least for the right of postprint archiving. If it does not let you retain the right to archive your postprint, then ask for permission to put the postprint on your personal web site. The chief benefit of postprint archiving is reaching a much larger audience than you could reach with any priced publication (in print or online). Reaching a larger audience increases your impact, including your citation count. Many studies confirm that OA articles are cited significantly more often (on the order of 50-300% more often) than non-OA articles from the same journal and year.
Deposit your data files in an open access repository along with the articles built on them. Whenever possible, link to the data files from the articles, and vice versa, so that readers of one know where to find the other.
When asked to referee a paper or serve on the editorial board for an open access journal, accept the invitation.
If you are an editor of a toll-access journal, then start an in-house discussion about converting to open access, experimenting with open access, letting authors retain copyright, abolishing the Ingelfinger rule, or declaring independence (quitting and launching an OA journal to serve the same research niche).
Volunteer to serve on your university’s committee to evaluate faculty for promotion and tenure. Make sure the committee is using criteria that, at the very least, do not penalize faculty for publishing in peer-reviewed open access journals. At best, adjust the criteria to give faculty an incentive to provide open access to their peer-reviewed research articles and preprints, either through open access journals or open access archives.
Work with your professional societies to make sure they understand open access. Persuade the organization to make its own journals open access, endorse open access for other journals in the field, and support open access self-archiving by all scholars in the field.
Write opinion pieces (articles, journal editorials, newspapers op-eds, letters to the editor, discussion forum postings) advancing the cause of open access.
Educate the next generation of scientists and scholars about open access.
(From What you can do to promote open access written by Peter Suber)