Roach, they are a total mystery to me, they are all I fish for now. There seems (to me anyway) that there is no pattern, no one method to concentrate on? Every trip is different; rigs, bait, methods, etc. It's coming together a bit now with my average size increasing. I have a good run of decent roach and then normal service resumes and I am back to square one? They are absolutely fascinating.
There is something special about roach when anglers like Walker, Wilson, Miles, Bowler, Lampard, Braddock are/were such enthusiasts!
New methods and baits have been introduced. Aknib rightly mentioned the helirig for roach. It is normally used with very short hooklinks and maggots but it works with slightly longer hooklinks and wheat. There are flavourings and pellets which are definitely preferred by roach.