This is something highly personal. What works for someone else won't necessarily work for you. And you'll probably find that most of the "pro" clothing makers use very expensive software, such as 3dsMax, Rhino, or Lightwave.

If you're planning to buy a software package, try before you buy. They all offer demos you can download and play with. You don't want to shell out $3,000 and then find out you hate it.

For free programs - again, I would try several and see which one you like best. Wings3D is probably the most popular free modelling program among Poser users. But I couldn't do anything with it. I love Anim8or, though - I was making usable props within an hour, no tutorials or manual needed.

You might want to give the Shade demo a try. It's from Curious Labs, so you get a discount if you own Poser. $49 for the LE version, I think - a great deal for what you get, IMO. Unless the Shade interface drives you nuts, of course. :-)