I don't normally buy crochet patterns. Half the fun is figuring out how to make what I want. Once in a while, though, I find something really pretty that someone has put a lot of time and effort into. I found some really beautiful and intricate flower patterns on etsy a few weeks ago and I've been making tons of little rose appliques. I was really impressed by how realistic her flower patterns are. They call for very fine thread (size 20 crochet thread) which helps get that shaping. Here's a link to the pattern that I bought:
The shop is Happy Patty Crochet and she has tons of amazing flower patterns.
While the pattern is easily accessible, size 20 crochet thread can be hard to find for a good price in the colors you want. I've ended up trying out a few alternatives. Embroidery floss and thread for friendship bracelets have turned out to be some pretty good options. The main benefit of course is the color availability. Easily hundreds of colors in solids, variegated, metallics, etc, but in order to get the correct size for a 1mm hook, you need to work with just 2 strands held together, so there's a lot of thread separating to do. For the friendship thread, you need to separate the two strands that are twisted together, which weakens the thread and can cause it to break if you're not really careful.
The rose in the photo above is made with three colors of friendship thread. In the last picture is the thread before separating the two strands. Once separated, the strands have a fuzzy soft quality that squishes the stitches together. I really like how the final piece comes out, but the thread does break a lot so it's a pain to work with.
I love making really small projects and this finished flower is about 1 1/2 inches across. Really fun!