I agree with @duChossois! I personally like to wear a lightweight liner under a mitten. My fingers run cold (and perhaps my circulation isn't what it used to be) so I actually really love winter running in my Outdoor Research Meteor Mitts (yep, these are more like ski/snowboarding mitts) but I will wear them without the bulky fleece under mitt. As a lighter weight option geared more toward running, I have older Saucony running specific mittens that have an ultralight weight over mitt (like a very light shell material) that go over a liner glove. These have also worked for me (surprising warmth for little weight and they really pack down). I can't find them anymore online but the overmitt looks a lot like the Inov-8 All Terrain Pro Mitt. The combo gloves with the mitt piece that you can pull over your fingers (also known as flip mitt) have never worked for me (just not warm enough). Obviously with the heavier mitts, you will have to pop them off to use your phone. Good luck! I'd love to hear what you end up with and if you like them since my old Sauconys sadly are not going to last forever. 

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