Ditto on the air blower. I bought a larger one from Jessops and then they closed down next day ... I blame myself for not buying two. A blower is the best way of getting rain drops off as well. Nothing else can avoid mud, grit, etc and lens caps are great until the wind blows some wet in them.
A blower is handy too as you can help out the other shooter on the lane.
PCPs have loadsapuff but nobody has come up with a simple lens cleaner adaptor to use some of it :-)
BFTA Secretary 2012-2014
CSFTA Secretary 2014-2016