The main thing here, is that when you start making snakes, you tend to flounder around for a week or 2 before realizing what the correct strategy for you is. By this I mean something implementable for you in the language that you're using.
The main thing about battlesnake is that you need to survive longer than your opponents.
This is the running principle behind any snake, no matter how aggresive.
When you have an aggressive snake, all you do is cut the amount of snakes left to give you a faster win.
When you have a peaceful snake, you actively avoid other snakes, and eating food is your priority, because you know you can outlast the other snakes.
Area control snakes attempt to box off as much area for themselves, and as such control the food spawns within that area. An amazing example of this is Tofu and Milktea.
There are many methods of getting the move beyond the heuristic, ranging from minmax to Monte-Carlo search trees, to random, to using some for