I think the thing about mud ponds is that you'll need a constant supply of fresh water, like from a well that you might spend $10,000 to dig and set up. If you have a good amount of yearly rainfall, this might take care of this, but depending on your bioload it may not be enough even though it keeps the pond full of water.
Depending on the size of the pond you'll also need to have clay brought in by the truckloads. If your soil is very dense clay then maybe you can skip this step. After this I believe you need some heavy equipment to pound the clay to compact it, so it holds water. This is stuff that I just gathered by reading a couple threads on clay pond construction for koi ponds - I thought I could do what the Koi breeders do to grow out fish in the backyard, but reality kicked in.
If it's allowed in this forum I can link a mud pond construction thread here or in a personal message/email.