Visiting your local supermarket...

The Cheese Counter - Always check out the cheese counter for any special offers - any blue cheese that's half-price or on special - is worth buying. It makes an excellent paste which can be frozen for later use.
The Spice Counter - Have a look around the shelves for spices. Cinnamon, Cumin, Allspice and Turmeric all make excellent additives to your bait. Try some of the curry flavours - always a good bet.
The Home Baking Section - See if you can buy any of these ingredients loose: Ground semolina, ground rice - these are excellent bulk ingredients for your baits. Milk powder, chocolate powder, milk/malt drink powders - these will add nutritional value and flavour.
Ready-made pastry - just roll it out, add some cheese, knead the mixture together - and there you are - instant cheese paste! It freezes well, and will accept any other flavours/colours you wish to add.
The Pet Food Section - Have a look at the dog biscuits - Pedigree Chum Mixer makes a great floating bait. Check out the dog chews and treats - the beefy flavoured chews are excellent carp baits on their own. .
Cat meat has become a favourite carp bait - use it direct on the hook or made into a paste. Try the different flavoured cat biscuits as floaters.
The Sweets and Confectionery Shelves - Is there anything worth experimenting with...? jelly beans, malteesers, etc., well worth a try, what have you got to lose - you can munch on them yourself if they don't catch.