Sure!

1: Don’t. He’s a pain in the ass.

2. Read the source material excessively. All of the canon appearances of Hakuba in the manga should be monthly reading homework. Keep facts straight, don’t stray into fanon unless you’re doing it intentionally. 

3. Read all of the Sherlock Holmes books.

4. Familiarize yourself with England… London, especially. If you can go there yourself, all the better.

5. It’s just as important to look at the things he dOESN’T DO/SAY/ACT ON as the things he does. Figure out the reasons why.

… but seriously don’t. He is a lot of work.

edit: GET COMFORTABLE DOING A LOT OF RESEARCH. The damned detective doesn’t like to be wrong, so if you start letting him say things, you better be willing to write a fricking 10 page research paper on whatever he’s interested in and I am not kidding he will get on you for proper formatting, citing reputable sources, and so on. He’ll also want you to TRY most of the things that he’s interested in so you can accurately describe it.