ok most sprites images are divisible by 2
some usual sizes are
8x8 16x16 32x32 64x64
most media design for monitor output is at 72 dpi.
You want to keep a copy of your work in PSD so u can test
different file exports for varying degrees of features.
eg: alpha channels...
some sprite media images are a series of images in a strip on a raw colour background.
imagine a series of images in a ascending animation frame layout evenly spaced on a raw background colour.
try to keep track of what colours u use so u dont use the alpha colour in the sprite colours.
creating a layer for each sprite and one for the background saves tonnes of time re-editing and positioning them.
You can change the background colour very easily in this fashion.
get to know the ruler and grid tools and lay down rulers
at the center points where u wish to lay the sprites.
cntrl r
You can snap them to the ruler without the hassle of having to do it manually.
If u explore 3d packages and models for a 3d look then u can render them out as flat files.
I have a 3d to 2d render script on my site if u want to have a look or you could render from a 3d package so u have more control to acheive a 3d to 2d look.
Any 3d in Photoshop requires good old fashion know how and skill with producing an illusion of 3d.
Shop has some distortion features that compliment that.
onion skinning is an old term used for basically being able to see multiple animation layers.
You can achieve this in photoshop with the layer opacity.
Other animation packages like macromedia flash have similar features with onion skinning.
If u type "Sprite creation techniques" or similar keywords into www.google.com you will find a plethora of information.
if your question about 3d modelling wasnt related to sprites
then you could take a look at a variety of 3d packages that are free on the web using google.com again or download.com to get the freeware versions.
I personally like milkshape / amapi / 3dcanvas /truespace 3se and just recently cinema 4d
theres heaps of free and not so free and home grown and commercial applications,
The industry and tools seems to be pulsating polymorphic magma when it comes to a "do it all application"
or due to version updates never relenting with new methods features and abilities.
The bar is raised each time with new features and tools.
smaller applications spin off that help with aspects if you choose the cheap freeware/shareware options but it can still do the job, You may need 3 tools where as one expensive package would have them colalted into one package.
i hope some of this helps
