With the VP9.....I roll my primary hand over the back of the pistol like the one Tam posted with the 1911 and can do this one handed and physically confirm with my pinkie. I prefer to additionally control the front of the pistol with the support hand from underneath using the front cocking serrations. This gives me a ton of control of the pistol, the support hand allows an extra layer of control and muzzle control, and nothing is near a trigger. Different people, different guns and different situations may require a different procedure. This is an administrative technique that many try to place in a tactical use.
This is one place I very much like the Pat Macnamarra "safety" rule of "Know the status of your weapon". Anyone who follows us knows we teach the four basic safety rules as two "Mindset" rules (1&4) and two operational rules (#2&3). Pat's take fits as an additional operational rule that I really like in that context. This is a means to confirm that operational rule, and it should be mastered to perform safely and you may need to adapt for different situations or guns. I will admit to a horrible, very long term embedded habit of mine to pinch check 1911's. If I was carrying one operationally or regularly again, it is something I would work hard to fix. Usually it is watching tv with an unloaded one.
Which leads to when I use the loaded chamber verification a ton....during dry practice. I check often. If the pistol leaves my hand, it gets checked everytime I start again.