1. Leverage your competition, by finding your top five closest competitors and spend your first round of SEO getting links from the top 100 sites that link to them. Once you filter out the ones that you won't be able to contact or you know can't edit their content to add another link, you'll be down to 20% of those 500 links. Now, you can do this in a day. Create an email, send it to each one of those guys asking for a backlink, telling them you're in the space and explaining why they should link to you. Don't pay for links, because it's not worth the risk of the google "police" finding out.
2. Long Tail. Don't focus on ranking for the super-competitive keyword such as "flowers", rank for medium-tail keywords that you can make some ground on with less effort. "flowers going away party", "flowers evil mother-in-law", etc. Related to #1, when you ask for a link, feel free to suggest anchor text in the link that helps you get what you want from that link.
3. Kickstart your on-site content strategy. Make a list of 100 articles that would help you drive traffic. Take the top 10 ideas and hire someone to write them. For each article, when you publish it, find 100 more people to ask for links to the article. Send them specific text and a specific page you want them to link to.
4. Authorities. Make a list of 10 authorities on your subject who blog or create content. Write an article that you think would be interesting to them, something specific that is in their space. Make the content really good. Contact them personally (phone call, even) and ask for links to the article. In the flowers example, academics focused on environmental issues related to flower farming, for example.
5. Directories. Build resource articles that cover your space in a way that focuses on your strengths. Find directories and ask them to link to your article. In the flowers example, an article on determining the proper type of flower for all special occasions or religious events.
6. Build links.
7. Build links.
8-10. Build links.