Started like a week ago with simplymaya.com's Apache modeling tutorial. I think the best way get better in something is to learn from others, how they work, think and so on. Even though you think you might know a lot about one thing, there still are endless tips and tricks that makes your workflow better. It's these small things that makes it so much easier, for examples in Maya I've never used custom shells before, it worked perfectly fine without it but it's these few extra klicks with the mouse that might make you tired of what you do.
Anyway take care