Looks like a nice first go at getting the technique down, as the others have said there looks like a bit of camera shake. With long exposures on a tripod you probably need to turn off the in camera/lens stabilisation as it can actually introduce vibration into the image. Some tripods have hooks on them, so you can hook your bag or something heavy on to help weigh it down and make it more sturdy.
A clearer, more interesting background would also help, and I find the big street light post on the left a bit distracting.
Samsung NX5 14.2MP (MILC or CSC) with 18-55mm kit lens. +1, +2, +3 and +10 close up lens. 50-200mm zoom lens. Sigma APO DG 70-300mm (pentax mount with adapter)
Olympus Mju 790SW Tough P+S
Husband: "Depth of field calculator? Does that tell you how far down your potatoes are?"