Thank you everyone for sharing your opinion.
GoogleSuccess,
Actually I did the first 2 tips you mentioned for my previous website which was about a quite competitive keyword, but it took over a year for it to get out of Sandbox.
It was on the first page of all other major search engines, but nowhere in Google. Now it's in the first page and one of the top 5 results in Google too.
But the idea of having to wait one year for your site to appear in Google is not very pleasant, is it?
So do you know any special tips or "tricks" to act as a shortcut?
Thanks,
Ladan