Does using a bigger crochet hook use less yarn?
If you are using the same pattern (same number of stitches and rows/rounds), a larger crochet hook will use up more yarn. If you are going for the same size of project (say a 36 by 36 inch blanket), a larger crochet hook will use up less yarn.
Is it better to crochet tight or loose?
You don’t want your tension to be too loose, yet you don’t want it to be too tight. You want it to be juust right. When you’re crocheting, you want your yarn to glide through your fingers at a consistent rate. You shouldn’t be straining your yarn or letting it hang loose.