The optimal open-access strategy today: open-access publishing (5%) http://www.doaj.org/ plus open-access self-archiving (95%):
Open access is possible today for 5% of articles by
publishing them in open access journals, and for at
Least 55% (but probably closer to 95%) of the rest
by self-archiving them.

    The optimal dual strategy is hence to
(1)publish your article in an open-access journal
 if a suitable one exists  and otherwise:
(2)  publish your article  in a toll-access journal
 in your institutional open-access eprint archive.