I’m a professional character artist/product designer in the hobby wargaming industry, so I’ll try to answer your questions and give you a few pointers. To do this on a production scale, I find ZBrush to be essential for my work, and use Blender as my main supplementary poly modeling tool. As a beginner, though, I think Blender could definitely be used to create a 3d-print ready miniature from start-to-finish, but you might have to translate some of my ZBrush steps into Blender.
A primary reason I do not bother creating fully-detailed print models in Blender is that VBOs are not yet implented in Edit Mode, so Blender is too slow to properly edit/boolean very heavy (multi-million poly) models. It can manage a couple million polys at a time in Sculpt mode, but that doesn’t always cover my needs. You may find that you do not need to create insanely detailed models, though, in which case Blender may be enough. One very important difference between video game/film character modeling and 3d-print character modeling is that a 3d-print character model cannot benefit from visual tricks like smooth shading, baking normal maps to a low-poly retopologised model, subdividing only during renders, etc. All the detail that you wish to be present in your printed 3d model, MUST be present in the geometry itself, and that means a very detailed, organic 3d-print model is likely to be far, far heavier, geometrically, than other kinds of model. A high-resolution character in a video game might be 10-15k polys after retopology. A very detailed 3d print character might be 20-30million polys prior to decimation, and 500k-1M polys when sent to the printer.
To answer your question about process, there are a lot of parallels between character modelling for video games and 3d print in the early stages, but they diverge later in the process in ways that I find can give video game character artists a lot of grief in their first attempts at modeling for 3d print. My pipeline generally goes a little something like this: 1.) Rough concept sketch and collection of image reference 2.) Low-Resolution geometry/placeholders/roughing in 3d volumes in ZBrush 3.) High-Resolution solid modeling assets in Blender, then bring them into ZBrush to replace placeholder geometry 4.) High-Resolution sculpting of organic objects/characters/creatures in Zbrush 5.) Hi-resolution surface/panel detail pass in ZBrush 6.) 3d print preparation consisting of boolean merging/subtracting the various model components into single-shelled (no intersecting geometry) solid components based on how they will be cast (or just merge them into one solid body if you are only printing, and not casting duplicates) 6.) Decimation and STL file export from ZBrush, then final STL cleanup/error repair in Netfabb (free basic version available) or Meshlab (fewer polys = fewer STL errors… for a fully detailed 32mm scale character, I target around 400-600k triangles. Rare is the model that I allow go over 1M triangles). 7.) Double check the physical size of your STL file in Netfabb/Meshlab… it’s surprisingly easy to type in an incorrect number during STL file export and find that your printed model is too big or small.
Hopefully that’s enough to give you an idea of a possible workflow. In truth, there are far more considerations that I won’t go into for now. You have a much easier job if you are just printing your model and not casting it, otherwise you have to deal with splitlines, pinch points, bubble catches, proper draft angles for release from moulds, part thickness, surface detail height, and on and on. For simply printing, you should just pay attention to making sure your parts aren’t too thin and spindly, or they will break. For self-supporting parts (arms, weapons, spears, you-name-it), I always try to give myself a 1mm minimum thickness as a general guideline, regardless of the intended model scale. There are times when you can break that rule, but it’ll take experience to know when.
Also, another poster Richard Marklew mentioned that the 3d printer capability is important. Here are the numbers I like to go by. For general purposes, I find 30 micron print layers to be sufficient for most cases. As you create smaller scale models with finer details, 20-25 micron is better at keeping tiny details very sharp. Obviously, if you can print at even higher resolutions, your results will be that much better, but these numbers will get you professional results. Higher than 30 micron does not cut the mustard in my estimation… you’ll start seeing a decrease in detail and maybe even ugly layer “stepping”. When modeling, making your surface details relatively bold will also help your end result. I try to always extrude small surface details (bolts, rivets, zippers, etc) by at least 0.2mm… smaller than this and they’ll disappear. Bear also in mind that your printed details will also need to survive a layer of primer if you intend to paint them, which will further soften the detail. These details may appear to be overbold on screen, but remind yourself how small they will be in the real world. When I’m sculpting, I’m always reminding myself to “go bold, or go home”, lol.
I hope this answers more questions than it creates, but you can ask followup questions if you like. Good luck!