One of the tips is to try and read the preamble once over and then on the second reading look only for the stuff to do with the clues. Once you know how the clues work, and can solve a few of them, then the rest is usually rather easier to get into and all that horror about "solvers must then translate alternate entries into Latin according to a quotation found in blah blah and then move corresponding answers in a manner described by extra words in down clues..." can become rather easier to decipher.
It becomes easier with practice, but certainly some puzzles can look intimidating at first! Often they aren't as bad as it seems, eg the recent "Game of 15" had a hideously convoluted preamble but was after all fairly easy.