I really don't know how much valuable the methods are. Please read my views on the methods mentioned above:
Forum Posting:
Are you starting new threads in niche forums OR just posting in different forums randomly with a link to your site from the signature? A lot of forum puts 'nofollow' on signature links. Moreover, I am doubtful about the weight of 100 links from same domain!
Blogging:
Have you created blogs for your sites? Are you posting regularly on those blogs with a link back to your main site? Then these are internal links I guess and good for your site especially when you use keywords in the link title.
Commenting on blogs may not be much useful. The 'nofollow' issue is still there. And you need to write good (I mean not spam) comments to make the comment valuable.
Article Submission:
Can you please clarify this? Are you writing articles and publishing it to 100 article directories? Chances are search engine would consider this as just 1 instance. However, it may bring you some traffic although.
Directory Links:
With Google no longer liking directories, where do I get PR?
Press Releases:
A good process to get one way links if used properly.
Among the rest of the processes, participating in Yahoo! Answers may bring you some theme links, but I am not sure if those pages can pass you
PR at all. Anyways,
PR is not all that one should consider. The rest of the methods are useful to achieve online presence and traffic.
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The best way to get 1 way links is to create a good site design wise and content wise so that people become impulsive to link to you.
One more thing you can try: create RSS Feed of your blog/site and get it published in Feed directories. A lot of people publish Feeds on their own site to offer their visitors updated news. It's worth trying.