I curate by hand using a custom tool that helps me search/filter articles and basically find a mix of things I like along with things that subscribers tend to click on. I tend to avoid "click-bait" type articles with little substance and try to get a good mix of things that were popular with things that should of stayed on the home page more. I've been doing this for seven years now, so I feel like I have something that works... but ultimately you'll have to see if it fits what you're looking for. :)

A recent issue just so you can see an example: http://mailchi.mp/hackernewsletter/360