Proper 301 redirect to pass page rank?

I know it doesn't pass full page rank but what is the proper
way to do a 301 redirect for this purpose?

Right now I've just manually forwarded the pages in htaccess
using:

Redirect 301 /OLDURL NEW URL

But not all pages - there are still some not forwarded as the
site is massive.

Or to pass page rank properly do I have to use a site-wide
301 redirect?

My old site was PR4 and after almost a month the new site
still shows as PR0.

Also, if I was to remove the 301 redirect would the old
site get its rankings back? (It also shows as PR0 now)

Thanks,

BobbyG