Getting rid of acne is a bit trickier. The best tool to use is the stamp tool. It allows you to copy the texture around the acne and paste it above it. The rest is a lot like painting, after you've gotten rid of all the acne use the paint tool and the eyedrop to color the areas that appear un-even. It's always bet to use a soft brush with a low opacity, so the skin blends better.
Add in highlights with a low-opacity, soft, white paint brush on to the upper cheek to add more emphasize on the cheekbone's structure.
I've found a great trick for getting rid of skin redness.
Highlight the area that's red (in this case her nose) with the lasso tool.
Select color range, and use the eyedrop to select the red in the blemish.
Then desaturate the nose till all the red is gone. This will leave a greyish tint on her skin. Without getting rid of the selection go to photo filter and add about 88% orange.
This will replace the red with a more orange skin tone.
Use a combination of the dodge & sponge tool to brighten the eyes (the sclera); the dodge tool can brighten whites but sometimes it'll saturate it too, use the sponge tool to desaturate a bright yellow eye back into white.
Sometimes make-up is done in post. Here are some helpful tips to get rid of blemishes and acne.
The best way to change exposure is with the levels tool; Image>Adjustments>Levels.
You can adjust the input to make the darks darker and the whites whiter or the output to make the whites darker or the blacks whiter; giving you all the possibilites you'll ever need with exposure.
Adding an orange photo filter will make the image warmer. Image>Adjustments>Photo Filter
Tweak these settings until you find the look you're searching for
Shooting in RAW is a must; besides having more resolution than its JPG counterpart, RAW records more detail in under or over exposed areas. This allows for a wide range in post color and tone without it becoming grainy or pixely.
Since I shot her at the beach I figured a bit more saturation and exposure would be fitting. You can change these settings under Image>Adjustments>Hue/Saturation.
Every photo needs a little editing. While it's important to never over-photoshop an image, understanding the program fully is necessary for every digital photographer. Not all images will be edited the same; changes in color, saturation and contrast will varey depending on the mood the photograph conveys. Here's a guide for advance photoshop users that demonstrates some of the most common tweaks I perform: