I work with really tiny thread; what is normally called “bedspread weight” is just huge compared to what I work in. I like DMC Cordonnet. I use size 30, 70 and 100. For the jewelry, 100 only. At these small sizes, the only colors you can get are white and ecru. On the one hand, it’s sad to be limited on color; on the other hand, working in darker colors at this scale is difficult to the point of painful! So, for the jewelry, it’s white and sterling. Someday, when I have enough wherewithal to afford the jewelry findings, I will do ecru and gold and sell them for a minor fortune.
My favored hooks are a Boye size 11 for the 30 thread, a Prime size 12 for the 70, and a Boye size 13 for the 100. Steel hooks are not as uniform in size as larger aluminum hooks. And newly manufactured ones are just awful in the smaller sizes. Really and truly, they don’t make ’em like they used to. The shanks are all wrong. A while back, I went on a crochet hook shopping spree on eBay. I bought a whole bunch of steel hooks, did a compare and contrast, and picked out my favorite ones.
I don’t even know where Prime hooks come from. Possibly Mexico? I’ve never heard of them before, but I have a number of them. Lots of Boye, and one lonely Milward. Here’s a good overview of steel hooks, and lots of other nifty information on thread crochet.
Here’s a photo of my favorite steel hooks, sizes 11, 12 and 13 from left to right. The markings are millimeters.