Take a sewing class or something. I'm realizing that imagining things in my head and having a stash of fabric does not a designer make. I've followed a couple easy patterns, but I wanna make the things in my head! There's gotta be a class (outside of getting a fashion design degree; I'm not that serious about it) that would make it easier for me to execute better.
But regardless, I finally pulled out my cutting board and sewing machine and iron and pins and blah-blah-blah and made Emberly the pinafore style top I'd been imagining for a while now.