I'd go with black high heels and maybe red beads or earrings but I love a pop of colour! It looks to me like there is a touch of red in it. Basically I pick out a colour from the dress and accessorise with that.
It depends how formal the event is, it looks like the kind of dress I'd pick for a wedding or Ladies Day at the races type events. Because the pattern is very intense I'd go simple with accessories and personally I wouldn't go for matchy-matchy.
I'd stick to just shoes, clutch bag and a bracelet and try and pick out a shade of flower for shoes and go for something high heeled put not strappy, a lowish front to elongate the leg and complement the lean shape. I wouldn't necessarily match the bag and shoes together, but whatever you choose don't clutter the dress it should be stand out item of the outfit.