If you have any students preparing for the Cambridge First Certificate exam this summer (or at any point throughout the year for that matter), I recommend throwing as many Use of English Part 4 papers at them as possible.  I had a student who took the FCE last summer and as she found key word transformations quite difficult, she asked for lots of past papers to practise with.  She commented that after a while, she found that a lot of the same expressions and grammar points were repeated and said that it helped her remember a lot of them.