So this is possibly one of the most talked about issues regarding motorcycles. Many people have different ways of securing their precious 2 (or perhaps 3) wheeled bundle of joy, but what is the best way?
In all honesty, there is no true way to completely stop a thief taking your baby (if you ever figure this out I would love to hear it). However, you can make it as difficult as possible.
[Image from: http://www.trimetals.co.uk/]
In the past 7 years I have had 2 motorcycles stolen and used a few different security methods. My first bike upon passing my test was a 1997 CBR600F. Owned for just over a year - I decided to stop at my grandparents one night instead of heading to my parents (as I usually do) and left it on the drive. Next morning it was gone. Lesson one - never leave your bike unsecured and on show, even for a short period of time.
Case number two: a few months after this incident I went out and got myself a 1997 GSXR750 SRAD. One evening I went out to meet some friends at a bar. The chain I had didn't quite reach the post, so I put the bike as close as I could, popped the steering lock on, disc lock and put a chain around my lid and rear wheel and locked my winter gloves under the pillion seat. Two hours later that was gone too. Lesson two - if you are going to put a chain through the bike, make sure it is through a fixed solid structure.
After this I got a bit OCD over my bike security. I went out and bought a 2001 CBR600 FS1 (and I am going to say it - the best bike I have ever owned). On this bike I had an acumen alarm, paging unit, chain and if I felt really overprotective a disc lock as well. What is a paging unit you ask? Well... it basically ran on an Orange pay as you go sim card and text my phone whenever movement was detected. I could also send it instructions to find out the battery level, set the alarm off etc. Yes it was a cool bit of tech, but I don't think it did my battery any good. A modern example of this would be the acutrac systems which you can find out about here: http://www.acutrac.co.uk/. On the plus side... this bike was never stolen. In fact the only reason I sold it was because of how much it cost to look after it in parts and maintenance.
On my next bike (and my current 2008 SV650) I pretty much stripped down to using two things - an alarm and a chain. The alarm on my 1995 ZXR400 was a £20 cheap thing that talked (yes very odd...) but the flashing blue light did help to keep people away (plus the strange dude voice telling the thief to step away...). But more importantly I make sure the bikes are secured to something fixed and solid with a decent CAT 3 chain. I currently use a mammoth 1.8m chain with a shackle lock a bit like this:
Best practices for using the chain are to put it through the frame of your motorcycle and then round the fixed object. If you can't get through the frame then at least pop it through the wheel (but these are easier to remove for a thief).
If you want to add disc locks and paging units that's fine too, but using an alarm and a solid chain should be enough. As I have said, if they want it they will have it one way or another. Also, check out security anchors if you need something to lock it up to when at home. There are a few decent ones, just make sure they have a high category rating.
I hope that helps solves the dilemma somewhat, any questions throw them my way and I'll see if I can help further :).