Currently, I use paper towels for one snake and hemp bedding for the others. I have also used wood chip and shredded newspaper for all my snakes when I started out.
*Paper towels:
PROS- cheap, easy to clean out, easy to notice when your snake has poo'd, won't cause problems with snake ingesting it.
CONS- not very aesthetically pleasing!
*Newspaper:
PROS- pretty much same as paper towels but if shredded your snake can burrow easier. Also, you are doing your bit by recycling!
CONS- some people metioned problems with the ink running (or maybe it was problems if the snake ingested it??) and also not very nice to look at.
*wood chip:
PROS- Looks nice, easily available from reptile shops or hardware shops, allows snake some degree of burrowing if its deep.
CONS- well I simply didn't like it. The brand I got was very 'chunky' and didn't feel as if it would be 'comfy' for my snakes. Problems with ingestion if you feed your snake in the tank. Harder to spot clean (cant see the poos as well)
*Hemp:
PROS- by far the best substrate I've used. Its relatively cheap, makes for great burrows for my snakes and is not 'chunky' like the wood chip. Kind of like bark mulch, I think
Also seems to keep smell to a minimum and is quite absorbant!
CONS- not as easy to clean out (spot clean) and again, you couldn't feed in the tank if you use this.
That's all I've used, and pretty much all thats available to me anyway. I think I remember someone saying that pine shavings are a big no no because they are poisonous? Can't remember that well because it isn't available up here so I didn't take much notice...
HTH anyway!