I have never had any formal training so these are things that I have figured out on my own, or borrowed from other sources.
1. I keep the clay moist by storing it in vacuum seal bag with a moist towel tucked in with it. This is good for short periods, days not weeks. The plan is to use all the clay before it dries out, so at this time I don't buy the 50 gram packs unless I know I am going to use it quickly.
2. When attaching two dry (prefired) pieces together I not only use the syringe type clay as a glue but I also moisten both surfaces. This is borrowed from pottery classes.
3. Olive oil does NOT work for me. I spent a little extra money and bought the special hand conditioner used specifically for working with metal clay.
4. Collect all prefired dust. This can be from the residue left on brushes, or from small bits of dried clay left on the work surface. Also, when sanding a dry (prefired) piece I lay a piece of cardstock on my surface to collect all the fillings. These can later be rehydrated and used again. You would not believe how much clay is saved. Also, when using a wet brush, the brush is rinsed in a container that will collect the clay that stuck to the brush.
5. Silicone molds are AWSOME! Carving stamp pads are AWSOME! Both are great for creating your own unique forms and textures.
6. I use polymer clay to shape more intricate items, bake the polymer clay and then use silicone molding material to make a flexible mold. I can then take my time with the poly pieces without worry of the metal clay drying out. I then use the silicone molding material to make a mold of the item. These molds can also be used over and over again. I just press the metal clay in the mold and pop out when dry.
7. A tissue blade, originally purchased for polymer clay work also work very well for metal clay.
8. I use a silicone spray to spray my tools and molds. I also spray a small amount onto a paper towel for use with smaller tools and the tissue blade. This spray keeps the clay from sticking to any surface.
Metal clay is some sticky stuff. Not sticky like gum, but it wants to grab onto anything that touches it. Hope this helps, I am no teacher and I am not in a guild, but these are things that have helped me along the way.