1. Plot as per vastu should be square of rectangular in shape. Square would be best. If it is rectangle then the ratio of length to breadth should be1:2 and not more than that.
2. The ground level should be higher in South & West rather than North and East.
3. Plots facing North or East are better than those facing South or West.
4. A canal, a lake, river, nallah, a big well or pond should be in north or east only.
5. Heavy construction or mountains should be in west or south of the plot.
The source
http://www.vaastuinternational.com