How uniform fields obtained between a set of electrodes in High Voltage Engineering?
The basic solution would be to have two finite plates, but to make additional electrodes to homogenize the field. 

The real configuration looked 
like a wide cylinder with two disk electrodes at the bottom and at the top. The side wall consists of many same-sized insulated rings, connected in series with equal high resistors R. The bottom-most and the top-most rings are connected with R/2 resistors to the disks.

With such a design we get a uniform potential gradient -- i.e. constant field within the cylinder. 

UPD: The idea behind is to force the same distribution of electric potential along the side wall of the cylinder, as one would be in case of infinite electrodes.  

Imagine an infinite charged capacitor. Then put there a column conductive rings, so each of them has the same potential as the initial field. You have got fully shielded volume with uniform field. Then cut out everything outside the cylinder. Viola! The purpose of the resistors is exactly to make  a linear distribution of the potential along the side wall.