telegraph sudoku

[johnny37]

Anyone play soduko in the Telegraph? I have the moderates cracked and have gone up to the toughies. Had a couple of successes at the start but am getting stuck now. Is there a technique for these which is not obvious. After exhausting all the usual checks, what should I do next? ps I have noticed that their moderates are harder than some other papers which have a five star rating but are actually quite straightfoward.

[BilSuth]

There must be books on techniques but my first step is to fill in each number, 1 to 9, throughout the grid by deduction. I pencil in alternatives, e.g. 1/2, and where two such occur in any line or box, 1 and 2 can be eliminated from all other squares in that line/box. Similarly with less common 1/2/3, 1/2/3 and 1/2/3 three-way alternatives.
I double check each set of alternatives systematically in case a subsequent number filled in now eliminates one of them (e.g. 3/5/7 may now by reduced to 3/7).
Sometimes, if stuck with a series of alternatives throughout the grid, I try simple trial and error. If you can be bothered, this means copying out the grid with all comfirmed numbers. Then assume the first 1 of a 1/2 is correct, giving you an inevitable 2, etc. If it doesn't work out, then the first 1/2 must have been a 2 (and not a 1, as you supposed).
Generally, I don't do harder ones now as I can't afford time of sustained concentration, and I know I can do them - eventually - anyway.
Hope this helps at least a wee bit.
p.s. I regard the definition of "alternative" as limited to only 2 possibilities as pedantic!