Thanks to the myriad of advice elsewhere on here, managed to reduce a 6 metre conifer to around 1m3 (bagable). Now I've just got to figure out how to get rid.
Check if your council will take away garden waste. Wandsworth does (within certain limits) if its bagged up in normal sized rubbish bags (ideally green).
A small bin type incinerator can be good if you don't have much space:
http://www.diy.com/nav/garden/garden-tools-equipment/compost-bins-incinerators/Sankey-Galvanised-Incinerator-1204-9218301I reduced several very spiky/scratchy/stabby bushes and trees in my garden to about 10m
3.
Luckily the in-laws had left their car with us when they went on holiday so over the last couple of weekends we've made 4 trips to the tip (taking one 'Midi Hippo' bag - about 1m
3 - with us each time).
Still have about 2m
3 to get rid of (and no car now) but the local council will take 3 bags of garden waste away per week with the usual garbage collection (it gets incinerated) so I just have to spend a few hours chopping up the 2m
3 of stuff into 8" long bits to fill up green garden sacks. They'll then go out with the normal rubbish and disappear over the next few weeks.
Most of it can be done with secateurs, anything else requires a few seconds with a "heavy duty wood saw".
Garden is almost clear of nasty sharp/spiky/stabby plants which makes it a much nice place for a 3 year old to play in.
I'm on call next weekend and I have to be within 30 mins of my laptop (and a decent network connection) the entire time, so the garden is perfect. I should even be able to have time to dig out the majority of the main roots of those trees/bushes too.