I'm starting to think ahead to projects that I may build in the future on my DIY MDF cnc machine. I will at some stage want to make something that is double sided - the software side I can work out on my own easily enough, but I'm having a little trouble working out the hardware side of things.

How can you ensure the best possible alignment for double sided machining?
Are there any alignment approaches or stock mounting methods that can help?

I can see a lot of room for error in this, so any info would be very helpful.

Thanks

Tom