I've gotten quite lazy at work - my old chinese 125 used to get chained to the railings (that was when I was a lad, new to the game). Then I bought a nice new disc lock for my Fazer when I got it. I used to use it, but then my brake discs warped costing me a small fortune and the paranoia said it was the brake discs fault (absurd I know), so since then I haven't used it, at least in works car park.
If I'm somewhere I'm not keen on I will use it on the back brake (I haven't just spent £250 on that!), but very rarely.
In most cases it's steering lock only.