Ask HN: Advice on building a community from scratch?

I've recently launched a website/forum/community to help others use up their soon to be wasted food.

The idea is to help people by providing them with ideas and recipes. These ideas are provided by a community.

I believe it is a skill to look at ingredients and have a basic understanding of what to cook. That skill like any can be acquired by chipping away day-to-day.

I'm wondering if anyone here has any experience in building a similar type community and has any lessons to share or points of failure to watch out for.

Or if you have any other input?

For reference: gidfid.com - is the site.