We clip a good 6" strip right down the back to tail. Also clip out tail if its going to be inside for a long period.
We have Galloways and this strip has really stopped them sweating on those still winters days.
We use Oster Shearmaster clippers bought from Euroclip.
www.euroclip.co.uk
Also use this company for new blades and sharpening etc, they are very helpful and can return your clippers very quickly.
Only precaution i can advise is never reach through side of the crush if your arm can be crushed/broken by a startled beast!
Happy clipping!