Drainage is one of the most important factors to consider when planting fruit trees. If you have heavy clay based soil it is important to plant your fruit trees into a raised mound which improves the drainage and gets your trees off to a good start.
Dig the hole into the ground as normal and then create a mound, with compost and the top soil from the hole. In these pictures I am planting a coconut, as I have heavy soils and coconuts grow along our sandy coastline I added a wheelbarrow of sand to create my mound.
To reduce competition from weeds, I recycle my old newspapers 8 sheets thick, which keeps the weeds at bay - for a little while at least
and then I cover this with a healthy layer or organic mulch, lucerne hay is perfect to use as mulch as it is rich in notrogen and feeds the trees as it composts.