It may be taking a while but I'm getting there...Thing 21!
I'm not super-motivated with this, I must admit, as I have no intention of looking for another job any time soon but of course one can never feel totally sure that a terrible axe may fall on one's current job in the current climate.
I have been keeping an Evernote note on my job achievements / things I've done for a while now and I had a recurring to-do task to update it fortnightly. It only took a minute so not particularly onerous. (A recent changeover from Remember the Milk to Wunderlist has meant this stopped - now reminder back in place!)
I think getting my current job was the greatest success of my career as I was up against incredibly tough competition and didn't rate my chances! I did use a lot of the advice about job applications - I stuck right to the criteria and showed how I met it all - plus I used the lessons from a day course on Presentations to create something I was happy to present and so did it with a bit more confidence than usual. I also wanted it really really badly so I did a huge amount of preparation.
For me, the one thing I always lack - and I think this would be an issue if I went for another job one day - is management experience. I did manage staff way back in about 1998 & 2001 but not for long - maybe a year at most. I never did appraisals or anything like that, it was just in terms of managing their workload and delegating tasks to them. This experience is not something I can see myself getting in my current role and it always seems impossible to progress to a management role without it (chicken / egg scenario). Therefore it feels like a particular hurdle I will never get past :o(