Just add a J.Crew Tippi sweater, and if you are investing in one for the first time start with a grey, then black or navy and then try for a colour (I went for red). The Tippi is an essential building block for your wardrobe, it is literally the T-shirt of knitwear and you will wear it with everything. It's got the perfect crew neck (looks great with necklaces or none), arm flattering 3/4 length sleeves and comes in the most gorgeous colour selection. Also the weight is perfect for in-between seasons (aka in the UK all year around!)
Flash back - with Jenna Lyons and this very same outfit in May last year.