Remember when eyeliner used to just be eyeliner? Me neither. Today the aisles of Sephora present you with every kind of formula you could possibly want -- exotic kajal eyeliners, liquid eyeliners in a rainbow of colors, retractable eyeliners, crazy hybrid formulas like Benefit They're Real! Push-Up Liner ... the works. You may find yourself wondering, "What's the difference?" So we had Wake Up For Makeup blogger Ivy Boyd show us (and tell us) which eyeliner formula is best for which eye makeup look. Here, seven different eye makeup looks perfect for whichever formula you gravitate toward (or for that new pen you can't wait to try).