My 82 year old Mum is very good at Cryptic Crosswords. I'm not bad either. Our local paper has two cryptics and a quick each day plus a nine letter Focus anagram word puzzle so there is plenty to practise on.
Today's Focus letters are EET
Find words with O in them of 4 letters or more, and the 9 letter word. 14 words is Good, 18 Very Good and 24 Excellent
Writers need a big and varied vocabulary and doing crosswords is a good way of expanding the archive.
The best way of expanding not just your vocab but your knowledge base is to read--LOTS. And in a wide variety of genres. By that I don't mean romance genres, I mean all sorts of books.
Try this fun site http://www.freerice.com