Whilst the winter wind and rain have swept most leaves from the trees and with it any chance of finding leaf miners, it is still worth checking any Evergreen Oak (
Quercus ilex) you happen to be passing as there are mines, both vacated and tenanted, still to be found...
Ectoedemia heringella
This species is known to be expanding its range, so definitely one worth keeping an eye out for, mines can be plentiful, as illustrated below
Stigmella suberivora

Dave