Any suggestions on estimating the amount of yarn you need if you don’t have a specific pattern? I want to replicate a sweater, and I’m trying to get a general idea how much yarn I need. 
TIA!
How about something like this?
What a great site!! Thanks so much!
“Knitter’s Handy Guide to Yarn Requirements,” by Ann Budd, is a neat triple-fold laminated card about the size of a #10 envelope that you can slip into your handbag or knitting bag when you go shopping for yarn. It lists yarn requirements by sweater type, size and gauge. It costs about $6 at yarn and book stores.