I've had MAC's Prep + Prime powder in my face drawer for quite a few months which I purchased after reading many positive reviews. However at first, I really couldn't get it to work for me. Initially, I used far too much product and didn't ever buff it into the skin properly - hours later I'd notice big white marks on my skin where the powder was sitting on the skin rather than being buffed in. Secondly, I first tried the powder at the height of my bad skin break outs - disaster. I didn't realise that the main ingredient corn starch, actually feeds the bacteria in your blemishes causing your break outs to worsen.
However, now my skin is back on track I've started using Prep+Prime powder again and so far I love it! It's a white translucent powder that has quite a mattifying effect on the skin, though it does allow some of your natural shine to emerge - on me it keeps any oil at bay for quite a long time: I do tend to sweep a tad more product over my skin later on in the afternoon as a touch up...
I use P+P as the final step in my make up routine, even placing it over my bronzer and blush. It dramatically reduces the appearance of pores and imperfections - I've noticed also that it photographs really nicely which I was quite surprised at as I'm used to` transparent powders leaving that icky white cast in photographs. In the photo above you can see just how white the powder is - it's a little scary using it for the first time but it does go on translucent. You can also see the one major downfall of the packaging, there may as well not be a sifter in place. This causes it to be a little messy to use, I'm always surrounded by a little white cloud of powder after using it!
Learning from my earlier mistakes, I only ever use a tiny amount of powder for my full face and would never use P+P if I was mid breakout. It has became a firm staple in my make up routine, I'm glad I persevered!
Lots of Love