Good ground preparation will ensure your planting has a high survival and growth rate. It will also have lower after planting costs with watering and weeding required.

Ground preparation for seedlings is no different to what is required for any other crop and should start 8-12 months before planting time.
The purpose is to provide a seedbed with good tilth, weed control and moisture retention.
If everything is done well, and there is good moisture in the sub soil, after planting watering is very rarely required.

The necessary steps should include the following:
- If there is long grass/ weed make sure to slash the area
- Spray after rain when you have fresh regrowth to get a good kill
- Deep rip along row to at least .5m deep. Moisture conditions need to be right,[better to rip when the ground is dry not when it is wet] especially in heavy clays to get proper break up of soil and no smearing of clays.
- After rain and further weed germination cultivate rip line with 3 or 4 tynes, mini blade plough, cultivator/mounder or small rotary hoe.
- Maintain planting lines weed free until time to plant
- If soil sets hard, rows may need a light cultivation before planting to ensure sufficient depth of soil to get a good covering of soil over seedlings roots.
- May apply a residual herbicide either pre or post planting.
- Sit back and watch them survive and thrive.

The design of your plantation needs to reflect the intended use of the plantation; ie shelter belt, timber plantation, wildlife habitat, erosion control, agroforestry, seed orchard, etc    

The main factors are: 
- How many rows to plant
:-How far apart are the rows
:-How far apart are the plants in the rows

Other points to consider should include:
- Vehicle access between rows for planting, watering,  slashing, weed control, mulching, harvesting, moving stock, etc.
-Size of your machinery to handle above

If you are planting an area to grow trees for fence posts you may plant just trees at a wide spacing. E.G. - Around Cobram this may be a 6m X 6m spacing. Or it maybe better to plant at a 3m gap and thin out later to both select the best trees as keepers and encourage taller branch free trunks for logs.
However if the intent is to produce a windbreak, shelterbelt and wildlife habitat it is best to keep closer spacing and a wide range of plant types/species to end up with good quality understorey and trees. Trees alone will, after a few years, drop their lower branches and allow the wind to blow through under the canopy. 

In the Cobram area this may be best achieved with a row spacing of around 4m and a plant spacing within the rows of about 3m and alternating trees and understorey. As you move east into better climatic conditions plant spacings could be closer.