How to make holes in plastic boxes?

[OM2]

I need to make holes in plastic boxes.
The holes need to be clean and smooth ones.
I've drilled and it comes out looking like a big mess!
I need to be able to do many many times so need to figure out how to do in a quick and clean operation that only takes seconds.

See below for what I've done so far:

Thanks.

 

[JohnD]

What sort of drill did you use? It must be cold.

 

[Harry Bloomfield]

Take a piece of steel pipe, of the correct diameter, heat it up on a gas flame, then offer it to the plastic, where you need the hole.

 

[Stivino]

Why not put rubber grommets on the holes?

 

[Old Salt]

Piece of timber clamped inside the face of the box to drill into.

 

[Nozzle]

Use a stepped drill

http://www.tooled-up.com/artwork/prodzoom/B-S20506.jpg