Examples of MeshFunctions

F[x_,y_,z_]:=Sin[x]+Sin[y]+Cos[z]+Cos[x]*Cos[y]*Sin[z];
ContourPlot3D[F[x,y,z]==0,{x,0,2Pi},{y,0,2Pi},{z,0,2Pi},
ContourStyle->{Blue,Opacity[0.1]},
ImageSize->400,Mesh->36,MeshStyle->{Blue,Gray},
MeshFunctions->{Norm[{#1*#3,#2}]&,Norm[{#2*#3,#1}]& },
Boxed->False,Axes->False,ViewPoint->{5,5,5}]