For most of my dives I have a small auto-retracting reel I clip to my camera and then a D-ring on my right shoulder and just let it hang there until I want to use it. It has a stainless steel spring so it's somewhat rust proof and a kevlar cord so it's highly unlikely to break during normal use. If your camera is heavier than a GoPro you'll need a heavier duty reel like what you'd use for your console. For the most part I can easily grab the camera when wanted, it stays tethered to me, and when I'm done using it I just let it go. I will give the caveat that handheld video gets shaky so if you plan on using it a good bit use a pole mount. I use the pole when my dive plan is to include doing video (compared to a normal dive where I only want short clips). Also very useful when doing video of things you shouldn't be putting your hands near (things that sting, bite, cut, or otherwise wish you weren't there and have the means to make you leave). For what it's worth, any new divers probably don't need excessive camera gear, just a camera and the means to keep hold of it. You wouldn't want to get so overloaded keeping track of your gear that you forget to watch your depth, NDL, & gas supply, then lose your buddy because you stopped to take pictures and he didn't notice.

Examples of video using pole mount vs handheld.

So I don't leave your actual question unanswered, here's an actual BCD shoulder mount if you cared to try that out. I haven't tried using a dedicated body type mount since I just don't care to leave my camera running all the time. You end up with a lot of digital footage to go through and I never seem to make the time to edit that much video. Therefor I usually do short clips which are easy edits. Of course feel free to video & take pictures however makes you happy since there really isn't a right or wrong here, only different. Sorry if I rambled on too much.