Any question answered...

I need to edit my 15000 word dissertation into 12000 so not that hard, but i find i spend a lot of words being vague or timid, such as writing 'x has a tendancy to' rather than 'x does'. Being more assertive once i've finished the essay (because i've proved my point by then) usually saves my 1000 words alone!

George Orwell would tell you off for using "has a tendency to" instead of the more concise "tends to" anyway - not so much for weakness of voice (non-specific terms are necessary in some circumstances - think statistics or ambiguous experimental results), but for padding the sentence with unnecessary prepositions and articles ;)

Conciseness is a tricky skill because the more formal the writing you're producing is, the greater the temptation to fill it with terribly grand-sounding phrases. It's easy to look at something that's accurate but terse and think "oh, it doesn't really look academic enough, better tart it up a bit". I think most of us do that unconsciously, it's not even a deliberate decision.