I do both. If an outfit really worked well, or if it's the clear way to wear a particular non-versatile item, I'll repeat it a bunch. But I also do lots of remixes.
Since a lot of my clothes are in a fairly limited range of colors and silhouettes, I think remixes are especially easy for me. It doesn't really take much creativity to decide that, say, a particular dress would work with a gray cardigan, heeled black booties, and dangling black earrings instead of a black cardigan, tall, flat black boots, and black studs.