The social icons are not high quality.
Off course you have a good start, but your nav menu is need polis. And also low level headings font family.
More space is not good in between content and sidebar.
It would be better a transition effect on hover for portfolio items.
You have good slider, but the footer is not professional like header.
Maybe you should reduce the footer modules.
Try to use good faced fonts.
You can add some nice color to overall design.