My two main concerns when buying a foundation have always been the colour and finish it provides. How it would wear, and for how long, would come after. However, that's changed in recent months. As long as the formula of the foundation is good, I don't mind if it's a shade too dark, or not as luminous as I'd like. This is because I now have products to help with these.
NYX has just brought out these Pro Foundation Mixers (£7.50), and they actually have less expensive dupes of the next two products, but these weren't available when I was in need of them. The Pro Foundation Mixer I have is in Luminous, which is a pale champagne shade with teeny tiny gold shimmer particles. Once mixed in with your foundation and blended out, you're left with, as the name suggests, a luminous finish.
I've been using the Soap & Glory Hocus Focus Illuminator (£11) in my foundation for a couple months now, and it's very similar to the Opal shade of the NYX Pro Foundation Mixer. It has that pearly finish, which gives you a more natural glow.
I've raved and raved about The Body Shop Shade Adjusting Lightening Drops (£10), and because there wasn't anything like them on the cheaper end of the market, I bought an extra bottle. I didn't need to because NYX now has its own version with double the amount of product in, but it doesn't take away from what this product does. Not only do I use this to lighten any foundations that are slightly too dark for me, but I'll add a drop when concealing around my eyes, just to brighten the area.
Not only am I now able to get the exact shade and finish I want, it makes my foundations go further. If there's any illuminators you swear by, let me know. I've just bought the Gleam shade by NYX, but I'm looking for some other warm/golden ones!