Just wanted to cover a few basics as far as ZBrush goes. Obviously its a bit of a learning curve going from physical sculpting to working in digital media, and I'm far from being an expert in the field, but I'd like to share a few of my most common tools and techniques I use - hopefully others will add to the list and we can all bounce off each other and try out something new and useful!
I tend to start using a lot of low resolution Dynamesh - a sphere first to rough out the shape of the anatomy of the model. At this stage, and right up until I add surface detail, I always turn the polish feature on as I like the overall look of the figures like this.
I build up the model using the move tool to create large surface changes, and the clay buildup brush to add in muscle structure and rough shapes - always re-dynameshing throughout and increasing the dynamesh resolution as I need it.
I create new subtools using mesh extractions, or occasionally by appending a new sphere, re dynameshing the subtool and then shaping it roughly. I always do exractions with the "Double" button disabled, and I use polygroup isolation (ctrl+Shift+click) to hide the inner surfaces of the mesh before deleting them (Delete Hidden), and then closing holes to make a solid mesh. This helps to keep the polycount down as I've found forgetting this step can end up in my system crashing from trying to process too much information!!
I've found that when adding surface details on items such as armour where I want a particular depth throughout, I tend to use the layer tool. I had some undesirable results with this where I ended up with overlaps etc which just didn't work, until I discovered the Morph Target. Set a Morph Target before you start sculpting on a particular subtool, and then no matter how many times you go over the same area, the depth of the detail is determined by the strength of the brush - and it works for subtractions too which is great for uniformed seams and engraved details too. The morph brush is like an eraser for this feature, so if I make any mistakes, I can simply erase any areas with precise control.
I've recently discovered the focal shift feature on the brush size, which seems to increase or decrease the fade/progression around the edge of a brush making a sharper or softer stroke accordingly. I'm finding a sharper stroke to be very useful with creating fine surface detail, especially where the intention is to have the figure printed in small scale as it makes the patterns and details more defined.
One of my favourite brushes is the Dam Standard brush, which for some reason is in the lightbox but not in the standard brushes menu! (I moved it now though so it is on mine). It engraves a mesh as standard, but kind of pinches as well as carving. Very useful for seams, hair, wrinkles and all sorts of other fine details.
HPolish is another great tool - used to burr off the surface of an area to create a more polished look - useful for armour and machined components like weapons, but for miniatures, I use it on everything to get the figure looking nice and clean. a low strength setting makes a very subtle effect, or you can really flatten out an area by making it stronger.
The only other thing I really use is the create insert mesh functions. Very useful for building up a library of bits for re-using on other models.
Oh, one more thing - decimation master! before posing its always worth running it through to reduce the polycount a bit - you seem to be able to take it really low before any noticeable loss of detail, and in 28-32mm theres not that much that's going to be noticeable in the final product.
Theres probably much more to talk about, but my brain isn't working properly at the moment, so if anyone else has anything to contribute please feel free to add it in!