I would like to state here and now that as far as filters go I rarely use them any more. My Polariser has not been on my camera for a couple of years now, and my ND X8 has been used twice just to dull down a day or two of bright light.
I have never found a lot of use for filters to be honest. I still shoot as though I have a roll of Fuji Velvia in my camera and nearly always use exposure lock, with the exposure being taken from a midtone area before recomposing. It works that way for me.
However, things may change! Why? Well, because I simply love shooting for black and white, and am forever trying to improve my technique, I came across Joel Tjintjelaar, a photographer who shoots long exposure black and white stuff. ( see him here http://plusonecollection.com/blog/2012/3/15/joel-tjintjelaar-how-he-thinks-and-creates.html )
I have to say that I have been totally smitten by his work and now long to give it a go for myself. I have never been disciplined to use a tripod in all my thirty odd years of photography, so now is the time to start taking my hobby a bit more seriously. It also means using at least a ten stop ND solid filter to get the three minute exposures I will need, and as I have the ND X8 to stack on top I can start achieving exposures of up to five minutes. Well, I never thought I would get so enthusiastic about doing something so very different to what I have been used to. Now, who was it who said one can’t teach old dogs new tricks?