Not necessarily best practices, but I recommend the Matasano Crypto Challenges to basically everyone. I make all of the developers on our team do them too:
Part of the point of the crypto challenges was to illustrate why people shouldn't work directly with low-level primitives, as a sort of antidote to the kind of advice OWASP gave out.
I'm not sure that the cryptopals chalelnges are the best way to learn exactly how you should be implementing everything, but I've found the knowledge that I gained from doing the challenges very applicable in my daily job and definitely helped further my understanding of crypto in a way that reading a book just couldn't do.
There is a theory that we practice on my team that you don't really understand something unless you try to break it. And this team regularly tells developers facts about their programs and systems that previously unknown to them.
I did the challenges years ago when you had to email in for them. Since then I can count at least five occasions where having done the challenges has allowed me to identify vulnerabilities in real-world crypto. I was usually able to recommend fixes that in theory made those codebases more secure. This is keeping in mind that I'm at best a hobbyist security researcher and just barely a professional developer.
I think there are about seven or eight people on Earth that I would trust to securely implement cryptography in their code. For the rest of us I'm happy with doing the best we can with libraries that make that easy (NaCl), and otherwise trying to find ways to break the thing. The cryptopals challenges help you do that, so that's where I'd recommend a developer start.