The product contains light diffusing particles that are designed to hide flaws and generally give your skin a radiant look. Now these kind of products, I've found in the past, tread a fine line between HIDING flaws and purely exaggerating them. In my experience, the finer the 'shimmer' particles in the product, the more likely it will have a flattering effect. I am pleased to report that this product has very fine particles and applied to the skin very smoothly. The Shimmering Skin Perfector is available in 6 shades and they can be viewed here http://www.beccacosmetics.com/COMPLEXION-Tinted-Moisturisers/c3_9/p23/Shimmering-Skin-Perfector/product_info.html. These are probably the most shades I have seen available purely for a highlighting liquid so I'm impressed that BECCA is making an effort as a brand to cater for different skin colours and types.
You can also mix it with your foundation for a lighter, glowy complexion (I wouldn't tend to do this as I need a certain amount of coverage but I can see how this would work really well for some people). You can also dab the product on your cheekbones and browbones to highlight certain areas. You would have to be really light handed with this product as it has a thicker consistency and is very concentrated so you would only need a teeny tiny bit! You can also mix the product with a moisturiser and apply to your body for a gorgeous glow.
Here's a swatch of what the product looks like on the skin. As you can see, you really don't need alot...
This is what the product looks like once it has been blended into the skin...
This would create a really nice effect under foundation as it's intense enough to show through foundation, but not so heavy that it makes you look shiny or greasy. You basically just get a very healthy radiance. My preferred method of applying it to my face would be under my foundation rather than over it. I prefer to use the Rouge Bunny Rouge highlighting liquid on my cheekbones are the consistency is alot thinner. This BECCA product does have a place in my makeup routine though and it has a more noticeable effect than other highlighters when applied under makeup. I like the fact that the gold shade is so wearable, I thought it looked too yellow at first but once you have blended it in, it really suits pale to medium toned skins.
I have had alot of comments before that people find these kind of highlighters give them a 'greasy' look and my advice to them would be to either apply it under their foundation for a subtle effect (using something like MAC MSF Natural to set foundation) OR only apply it delicately on the outer corners of your cheekbones (think along the lines of a 'less is more' approach). This will ensure that you have a lovely glow without looking overly shiny.