Starting a new crew is something I tend to do every few months and I always start it with the best intentions "I'll paint this crew to a decent standard" or "I'll completely learn this crew and practice with them" (or the most favourite "after this I don't need any more models") Things don't always work this way as I am prone to saying "good enough" and then coasting through the rest of a project.
Because of this I'll never be able to tell you how to master a crew or how to win a painting contest but what I can tell you is how I go about starting a new project.
First things first choosing a new crew.
I will either pick a crew box that I think has models that will help my current faction. I did this with the Red Chapel box, I brought the box just to have some belles to use with McMourning I then ended up playing Seamus exclusively for three months because the crew looked like so much fun.
The second way I choose a new crew is the tried and tested "ooo shiny" method. I see a crew that looks good and fun to paint and I then convince myself that I need a new crew to paint and... "I'll paint this crew to a decent standard" starts again.
Step two. Google-faux
As I'm at best a mediocre player and in all honesty a pretty poor one, learning how the crew works isn't too high on my list, the fluff and the painting always excite more me with a new crew.
I'll read any stories I can find for a new master whether it's from the main books, chronicles, the old books or just random blog or forum posts.
Once I have a good /feel/ for the master I start planning colour schemes, bases and any conversions I be able to do.
I also trawl the web here for inspiration there are plenty of places to find great paint jobs online, the Wyrd forum has a whole board of people showing their work. Twitter, Facebook and Instagram have hundreds of amazing painters posting their work everyday. I will also look at Cool Mini or Not for some general painted models. For more themed inspiration I go to Pinterest. When painting Yan Lo and currently while planning Kirai I set up a board of traditional Japanese and Eastern art and fashion. While working on Seamus and the Belles I had pictures of Victorian clothing which helped me focus on a theme.
Step three. Study
So once I have a scheme planned out and while I attempt to paint the crew anything like I'm imagining I will start learning the cards and working out how they work together.
I tend to be a bit combo-blind, all those filthy tricks and combos go unnoticed until someone points them out. Those someone's are very often on twitter or as I'm lucky enough to play in a fairly large group of Malifaux players I can also bug people in person.
The Before We Begin Podcast is amazing for learning about a new crew and will often be playing while I paint.
The Pull My Finger Wiki is also good for explaining what each model does.
After all this the only step left is to get the crew on the table and hope for the best.