The first rule is always location. It's hard to find cheap land in a urban area that has already grown tremendously. However, this does not mean that you go for a land which has is located in a location without so much as good road access. It's all about taking your time and energy and finding the right listing with cheap land on the market that is conveniently located. At least, make sure the get you are interested in is in a location that's likely to grow. Also think about the geography with the area, as well as the climate. When it gets too hot or too cold in some seasons, it might not be a worthy purchase, much more if you plan on building within the land.
Second step to take into consideration is the profitability of the cheap farm or hunting land available. While land is hardly proven to depreciate, normally it takes time before it comes from any profit. You have to find land in an area that is likely to grow, because growth will be associated with a land price increase. Even if you don't plan to sell immediately, it is comforting to know that you can get good profit from selling the cheap land for sale that you invest in.
Stick with proven markets, as opposed to buying some cheap farm land for sale in an area which is hardly known. This doesn't make much sense when you purchase a piece of land in the country, in which you know decades will pass prior to the area ever grows. Instead, buy land in an area that already has a spark for growth, before other folks seize the ability.
When buying cheap land on the market, keep in mind that the vendor will have a sales pitch ready, and will try to help you to buy the parcel. But take a moment and think about the buying decision. If you have any doubts, don't ignore them. Whatever the case, you can always look someplace else.