Capture is a unique product, and if this is your first time using Capture it can be an odd piece of gear to become acquainted with. It's a simple, versatile product - there are tons of ways to use it... and misuse it. Read this and you'll be up and running (in the right direction) in no time.
1. Screw in your quick-release plate with the provided hex key.
We can't emphasize this enough. You love your camera. We love you. To maintain a 100% secure connection between your camera and the quick-release plate (and prevent the unthinkable), give the plate a good crank with that hex key. Put that hex key on your keychain or in your camera bag, and periodically tighten your quick-release plate as needed (though if you torque it well at first you won't have to worry about loosening).
2. Try mounting Capture in different locations, but definitely try these positions first...
There's no wrong way to wear Capture. We're all different (we're snowflakes, if you will), and so is our gear. If you don't experiment with wearing Capture in different positions, you'll never find what's right for you. But, we've learned what's right for most:
Left backpack strap, at collar-bone level.
If you're using Capture on the backpack, this is the best mounting location for a vast majority of users. The quick-release button will face towards your center, making it easy to grab your camera. Having your camera up around your collarbone will generally give it more support.
Belt, just to the right of center, with the quick-release button facing down.
Having the quick-release button facing down makes it easy to release Capture with a 1-handed grab. When your camera is close to the center of your body, it's generally easier to walk around. If you have a particularly long lens, it might be more comfortable to wear Capture on your hip.
3. If you have v2, use the quick-release button lock, not the plate lock, to secure your camera.
Note that this does not apply to Capture v3. Capture v2 (and earlier) has 2 security mechanisms - one is a lock and one is not. Lots of folks confuse the two. To prevent accidental release of your camera, use the quick-release button safety lock, shown here:
To stabilize your camera in Capture (when shooting P.O.V. video or using Capture as a tripod head) use the Plate Lock, shown here:
4. Watch the Capture Setup video
This one is an oldie (shot back in 2014) but a goodie. It shows Capture v2 but everything in it applies to newer and older versions. Have a peep.