If your images are continuously coming out blurry with a lot of streaks (I'm not talking about it being out of focus), it's possible the blurriness is due to camera shake. Trying to steady a really heavy camera, using too slow of shutter speeds, & really strong gusts of wind are all possible causes for camera shake. Here are some tips to help reduce that.
1) Brace yourself against a wall, tree, or something very stable. You might feel stupid, & get some weird looks from people, but it'll be worth it.
2) Don't be afraid to have a tight grip on your camera. Sometimes I cringe when I hand someone my camera & they hold it in their finger tips as if afraid of how big it is. If someone accidentally bumped into you & the camera could fall out of your hands, then your grip is too loose. Hold onto that bad boy! It cost money!
3) Tighten your grip, but also tighten up your body. Bring your elbows in closer to your sides. If you're shooting horizontal/landscape, this is easy. When you rotate your camera for a vertical shot, your right elbow will probably go up in the air, so make sure to keep your left elbow tucked in.
4) Hold your breath. Or, slowly breathe out when you press the shutter.
5) Don't forget the follow through. Resist the urge to jerk the camera away from your face the millisecond you took your finger off the button, especially if you are teetering on the edge of I-really-should-be-using-a-tripod-ness. Wait at least one full second after snapping the photo before relaxing out of your photo-taking stance.