I just finished the Hip in Hemp Skirt that has been on the needles since 2011. I'm happy with the results; I won't hold a grudge---it's not the skirt's fault that it took me so long.
I did take Mere's advice (thank you!) and knit a few extra inches before I cast off, and thanks to Ravelry readers' notes, I realized I had not copied the cast off instructions, which required 10 rows of garter stitch. That added an inch to the length and thank goodness, I had enough yarn.
This skirt kept getting fuller as it got longer, and I was worried that I would need one of these to wear it properly.
If only I had read the other knitters' comments on this skirt BEFORE I started the skirt I would have known how to make it longer without making it wider, and at the same time, maintain the desired shape of the skirt. And I could have skipped all the math and logic and painful thinking that doing the calculations myself entailed:
If I were a more experienced knitter, I would have been able to figure out with my own little brain how to make the changes I needed to make with. It was embarrassingly easy! Just add one extra stockinette row between the increase rows---4 rows instead of 5. Duh.
This skirt took forever and a month to knit, has one bazillion stitches and I LOVE it!