Bluebird,
Super Sculpey (polymer clay) rocks!!!! It's my favorite sculpting medium out of clay, wax, epoxy etc. But for me, I have to "prepare it correctly" before I use it, here's what that means:
Mixing / Conditioning:
Using a 1 lb box of Super Sculpey (the beige stuff in the green flip-top box) add 1 black 2 oz color cube of Premo Sculpey and 1 white 2 oz color cube of Premo Sculpey (Don't use the Sculpey III color cubes if you don't have to it's not as good but it will work if you must use it with no other option) . Blend 1/4's of these products together until it's an even grey color. This makes seeing details / uneven surfaces in the clay easy and also makes the baked Super Sculpey not as fragile / brittle as it is without the Premo added.
Leaching:
Roll the clay into thin sheets (use a pasta rolling machine if you have one otherwise just a rolling pin) and layer it between sheets of computer printer paper (don't worry, it won't stick) and layer it like this: Paper, clay, paper, clay, paper, clay, paper... with paper on the very top. Then set a heavy book ontop and let it sit this way for 24-48 hours. What this does is extract the excess oils out of the mixed Sculpey and makes sculpting details a great deal easier because the clay is no longer Super Squishy. If it's still too squishy to work easily, roll it out and leach it again with new paper. Some batches of Sculpey are old and have little of the Plasticiser oils and some batches are almost wet with it and require repeat leaching. I check every box on the shelf by opening it and poking a finger in, I buy the firmest boxes I can find. You'll "know" when you have reached the level of firmness you like through experience. I'm so set in my ways that when Sculpey came out with their "Firm Grey Sculptors Medium" version of Super Sculpey for people like me (you can find this in a grey and green flip-top box) I didn't like it, it's TOO FIRM for my taste! In my case I ordered 10 # of it before they put it on the open market and I found that it crumbles too easily and I end up having to add Sculpey Softener (Plasticiser) back into it... I'd rather leach the excess out than add it back it's easier and less time cosuming.
Armature:
Most beginners don't realize it but sculpey needs an armature, which is basically a skeleton made of wire that goes inside your sculpture. All you must do is use 1/8" diameter aluminum wire (not galvanized wire it will break if you try to re-pose more than a couple times) and trace the basic angles of the sculpt. I use aluminum foil tightly wrapped around the wire as a "bulk" material and only use clay on the out 1/2" or so, you just waste clay to put it inside the body of the sculpt. To get the clay to adhere the to wire and foil armature wrap the whole thing in thin (18 ga) floral wire. This gives a "grip" for the sculpey to adhere to plus when you bake it it will cook from inside & outside and cure better in the oven . It is quite essential that you have a plaque or other piece of wood to insert the armature wire into for having your work "stand" before you. You do not want to handle / hold the work any more than necessary as warm hands deform clay! It takes getting used to to work this way at first but you'll find it's far easier to do solid clean work when you're working "hands off". I have a set of 3 or 4 different sized wood plaques from the craft store that I drilled full of 1/8" holes so I can insert armature wires for a figure in any pose. Saves me having to drill holes at 3 am when my neighbors are trying to sleep but I've got the inspiration! I buy all these items including the Sculpey at Michaels & JoAnn fabrics Craft emporiums.
Baking:
Make sure you're oven is the correct temperature or you'll boil your sculpey project -buy an independent oven thermometer (they're like $3 at the grocery store) cos there's nothing like sculpting a figure for 40 hours only to have it become a pile of boiling black goo in the oven! If you don't wanna buy the thermometer just cook it at 200*F (oven setting) and leave it in longer. Lower and slower is better than risking it by setting the over to 265*F (but your oven is actually 325*F) cos then it's bye bye hard work!
Repeat Baking:
You can "series bake" what this means is doing a sculpt in steps. I generally sculpt the anatomy of my subject and then bake it. Then I add the lowest portion of the costume (say a superheroes tights or knights main armour layer), then bake again, then do the belts and accessories, then bake again. I've baked up to 20 times on a single sculpture depending on details. After you bake the first stage the new (soft) sculpey will not want to stick to the baked stuff. All you do is smear a TINY bit of Vaseline (petroleum jelly) where you want to add more clay and then wipe it off (yes that's right put it on sparingly and then wipe it right off) all you aim for is a very fine film of vaseline- this will allow the new clay to stick perfectly easy otherwise you'd be cursing me for telling you to bake in stages!
Hopefully this will help you get started on the right foot with the amazing product called Super Sculpey if you have any questions feel free to PM me and I'll try and help you out as best I can.