The best option of all: don't dispose of things in the first place. Avoid over-ordering, and use things to their absolute maximum capacity before throwing them out.
If you've definitely finished with something, and really do need to dispose of it, the best thing to do is to give it to someone else who needs it.
The one everyone has heard about: sending waste of to be broken down into its basic form, and used to create new things.
Instead of taking waste to a landfill site, you can incinerate it, feeding the energy generated back into the national grid.
Sending waste to landfill is the worst option. It leaves non-biodegradable stuff lying around for years and years, taking up valuable space, and potentially poisoning the environment.
Warwick sends nothing directly to landfill - the figure referred to here is residue from the energy reclaiming process. To help us reduce this figure even further, make sure you re-use or recycle everything you can, and keep contaminated waste out of the recycle bins.