I came across a few sites that provide instructions on how to make babywearing items. I haven't tried any of them yet. If I do get around to trying out these patterns I'll let you know how wonderfully badly I faired. Sewing is not my thing, but some of these patterns might be do-able for me. Here you go:

No-sew Ring Sling
Maya Wrap Instructions
SlingMeMommy! Pattern (Click on SMM pattern)
Bravepages Adjustable Sling
No-sew Mei Tai

If you try any of these patterns and you feel so inclined, come back and share about it! Have fun!