My tip for this week, is when you are yarn shopping, make sure you also check the yardage you will need for a project against the yardage per skein of yarn to determine how many skeins you will need. It is better to have a bit of yarn left over than to not have enough. Weights per skein of yarn are a good general guideline, but the yardage you get per weight will vary between yarns.
I figured this out because I barely had any yarn left over from a 16 ounce skein of yarn when I made a size 8 knit for kids sweater, when the guidelines say 14 ounces makes an 8. Then I got looking at the yardage for that brand of yarn, versus what the guidelines say for how many yards you need for an 8, versus another brand that makes a 16 ounce skein of yarn. That is when I tuned in to the fact that the yarn I had used was thicker, so you get fewer yards to the ounce, verses a thinner (yet still 4 ply) yarn from a different brand. So in the future I will just have to remember that I cannot make a size 10 with just one skein of the thicker brand of yarn.
Yardage is also important and useful when you are working with a pattern that you can use different types of yarn with, and they give you how much yarn you will need in yards. Again, I would rather have a bit of yarn left over than run out, and need to scramble to try to find more yarn, and possibly not be able to find the same yarn I had bought, and then not be able to complete my project.