What makes a great (Listly) list? One that encourages others to contribute. Despite the fact that Listly lists are started by a single person (you), the most engaging lists are crowdsourced and contributed by many.
Here are some best practices when you start a list:
Start a list with at least 5-10 items. Anything less will result in a high "bounce rate". Anything more will reduce contributions/engagement on your list. You can always come back and add more that you left out in the first pass.
Leave some obvious items off the list - e.g. leave Pele off a "List of top Soccer Players" so that someone else can have an easy win and add it to the list.
Share on multiple social platforms. Listly makes it easy to share the list as well as individual items with a single click. When you share, ASK for help to complete the list.
Embed the list on your blog and encourage your audience to embed the list on their blogs as well. The further your content spreads, the more people will find your content.