Just done a quick whizz through the site to patch up all mentions of Blumenfeld's advice (which was passed on by Kotov and Webb in their best known books).  The advice is:

Blumenfeld's rule:

"It often happens that a player carries out a deep and complicated calculation, but fails to spot something elementary right at the first move. In order to avoid such gross blunders, the Soviet master B. Blumenfeld made this recommendation:-
When you have finished your calculations, write down the move you have decided upon on the score sheet. Then examine the position for a short time 'through the eyes of a patzer'. Ask whether you have left a mate in one on, or left a piece or a pawn to be taken. Only when you have convinced yourself that there is no immediate catastrophe for you should you make the planned move."

(see also the COMMENTS on this advice).
However, in the last FIDE revision of the rules, this practice is now considered note-taking, and is forbidden.  I don't know how many players are complaining about it, nor how many controllers coming down on it (after all, this is a habit of some years' standing for many players)... but it is illegal.  So what can we do instead?
Well, the idea is, to take a fresh look.  As long as you can make that last-minute check without the aid of props, you should do so.  Ways of producing a physical prompt or routine that don't require pen and paper include:

• shut your eyes for a second or two
  
• walk around your chair
• look at the board next to you then look back
• go and stand behind your opponent and see how it looks from their side
• slap yourself firmly (it works for TVs, right?)
  
• visit your private toilet facility
  

I wish everyone a happy and blunder-free New Year, although yesterday I managed to get the order of moves reversed, with dire consequences... Physician, heal thyself!