Adobe Illustrator is an amazing program for creating vector illustrations. Highly recommend!

CorelDRAW is quite good! I've used it myself for a variety of design projects and it's always come through with flying colors. Plus, it's relatively affordable compared to some of the other big name software programs out there.

Digital Fashion Pro is good - it can definitely help you create some great looking designs. But there's a lot more to fashion than just design, and if you're not careful, you could easily find yourself relying too heavily on the software and not getting the full picture of what's involved in fashion.