Now with added belly pan

[ZiggyCol]

And to add what cable tie says. Chock the front wheel to stop the bike moving forward and off of the stand. If your bike toples onto you and you get a footpeg in the eye it will make you say 'Ouch!' very loudly.

:lol

or alternatively strap the centre stand to the front wheel which will also stop you 'lifting' the bike off the centre stand whilst working on it - especially when doing something like undoing the rear axle nut.