I presume you mean basically a ball of fire on the end of a stick?
I think that tar-soaked rags would be OK, probably traditional, though tar his hard to light and doesn't burn bright. It does burn slow though, which is good.
I think it'd be kinda difficult to find a good mixture of something thin enough to light easily and burn brightly, but something thick enough to burn slowly. Obviously things like petrol and lighter fluid would burn too quickly, so I'd say for simplicity's sake, tar would be good, just keep in mind that it'd be a very smoky flame indeed, so try not to inhale.
Another option might be petrol and styrofoam. If you saturate petrol with styrofoam (dissolve the styrofoam in the petrol until it won't dissolve any more) you should get a syrup-like substance that burns relatively easily, though personally I think it'd be too dangerous and I've no idea how long it would last.
I reckon you should just get a flashlight, but I understand the desire for something more home-made...
You also face the problem that if you want a torch for camping, you'd either have to carry about two-foot-long sticks with tar-soaked canvas on the end, or you'd have to carry around tar and rags wherever you go, both of which seem pretty inconvenient.
Sorry if that sounded a bit defeatist
I do, however, recall that Ray Mears used a big torch in his Aboriginal Britain episode of Bushcraft. No idea what he used for it though...