how to plant my olive tree

All I know about olives is that they like good drainage, so you'd need to dig in a lot of gravel. I have some in pots - one nearly died with lots of scale insects & sooty mould, so I asked at the garden centre. They said re-pot in John Innes no.3 mixed 50/50 with gravel, & gravel layer at base of pot. They can do with very little water in Winter, but like regular watering in growing season but with good drainage as they don't like soggy roots. I imagine you would need to improve the clay soil & incorporate gravel, to plant in the ground. (After doing the above & pruning back hard, my sad olive now looking great!)

Mine lives in a large pot and I try to mimic the soil of somewhere like Greece. As Caz says, good drainage, they like it dry and warm, not soggy and wet.