Mate when making dio's just remember that you don't have to go out and buy heaps of expensive materials to make a great dio. Look around the house first and you will be amazed what you can find and use. eg - cereal boxs, margarine containers, plastic bottles and the list goes on and on.
You will have to go to the hobby shop and buy glues, plaster etc but we all have to do that at some stage when building dios. Now the most important thing to remember when building a dio is the composition you have to make sure that you don't have to much or to little on the dio.
Here's a tip on how I see if the dio looks ok, get the figure, vehicle, parts and place them on the base and then place the base/dio in front of a mirror and stand back about 60 cms. Kneel done and look into the mirror and look at the base/dio and you will get a different perspective when looking thru the mirror, and you will be able to see if you have to much or to little on it.
Ron