My wife and I built an adobe oven, in which we made pizza, bread, and some full on dinners. after breaking dry clay, and slightly sifting it (to get big rocks out), we wet it and mixed it with some dry native grasses (you want long fibers, not like your lawn). It should have be moist, but not dripping. It was tiring work, mind you. Using the loaf tin as your mould, make as many as you feel you need (I made about 25). Once they are dry, you can mortar them with more of the same clay, and the shape of the loaf tin adobes will lend itself to a nice igloo shape. Leave a door opening, obviously, and make a little door, out of the same adobe or wood, or whatever. Ours took three weekends, because we had to wait for things to dry. if you fire it up too soon, it can blow up (yeah really). This may be a bit too general I know, but it is more than I had when I started. That little mould was the perfect thing. Good luck!