First let me tell you I don't recognize what you are using, so just giving general tips.
Make sure to also use the same kind of tools e.g. brushes, that remotely look like what they used at the store.
Apart from that, I will second the lighting thing. I *did notice* that at the MAC store where I was given my first demo, that lighting was favorable to concealing what daylight reveals. If I didn't want to see the blueness below the concealer, I wouldn't have seen it. But I did. So, I complained and made guy apply more layers. Damn, it was still visible but I moved on because what we got to was a big improvement to what it was before.
I also noticed in start that my face looked just fine at nights but daylight was a killer. Daylight is still less favorable. Also, some sorts of lights make my everyday make up turn green so that is also a prob to have on mind.
So, what I found best works for me is apply some lipstick on face before concealer. That helps killing the blueness, in my case purpleness. I can see it done well in the mirror but female colleagues confirm it too... what I wear does look like greasy make up when one comes close, but no traces of beard shadow are seen either from far away or in close ups.
But then again, I have already had multiple face laser treatments. I did lose a lot of hair compared to what I started from. That said,
here is what I do. I somehow have big doubt it will work before any treatment, so if you would like to try, the general idea is primer + lipstick(s) + concealer(s) + primer + powder. I skip the foundation that would be between concealer and powder. If you would like to try, attempt to get a store to give you a free or a cheap demo. Then go out and make good photos so you can see results.
*hugs*
P.S.
Let me also tell one fail of mine. I got recommendation for Dior's Forever foundation. Oh my, that thing is made for those who don't deal with 6pm beard and beard shadow. It also shatters away. I personally couldn't cover a pimple with it for long. So, now I got a bottle to spend and would rather gift it to somebody who needs it.