kill a watt setup
D4-D7 are data lines Leave D0-D3 unconnected
E = Display Enable
RS = Display Reset
As you are probably only writing to the display, you should connect W/R to 0V
Apart from power and contrast, these 6 lines are all the data connections you need for 4bit operation. Always assuming that this is an Alphanumeric display, and your software is setup to operate in 4 bit mode. If this is a graphics display, the the above will not apply, there are different sorts.