Look out for easements. If there are any easements then they should be well out of the way, like right at the back of the block.
Ideally, slightly sloping to the road to allow for easy drainage of the storm water.
Depending on the style of the home you are planning a suitable orientation of the block to suit the style, so that you can include solar passive aspects in the building.
If the block is wide enough or deep enough to allow for multiple dwelling either immediately or later to maximize the returns.
There are many other consideration but it is so dependent on what your plans are that it becomes difficult to suggest all features.
cheers