Need to erect a 3 or maybe 4 course brick high wall at the front of property
garden. Only as a finish off to the garden and not for anything structural.

Question is would it be better to make a 4" thick concrete base or just lay
the first course on compacted rubble etc ?

Rented house so I don't want to go to huge expense just make it look nice
and for it to last a while

Any suggestions as to what to avoid topping it off with? I'm not keen on
those triangle topped stones so any ideas other than that welcome