Making the basic bath fizzie or bath bomb is pretty easy, but if you want to make something superior there are several things you can do. First of all the use of cocoa butter can yield a much harder bomb and a more luxurious bath. Simply substitute up to half of your oils with melted cocoa butter. Let your new mixture cool before using because hot or warm oil/water mixture will set off your bath bomb mixture much faster than room temperature oil/water. A quicker drying bomb can be achieved with the addition of kaolin clay, rather than using Epsom salts substitute with kaolin clay at the ration of 1 part salts to .5 part clay. Cracked bombs- cracks in bath bombs results from using too much liquid, scale back the liquid and you will have better results, you can also try adding in a few pinches of kaolin clay to your next batch to keep those cracks at bay. The bombs are still good, just not pretty. Bumpy bombs/\'growing\' bombs- too much liquid again, or too high humidity. If you live in a humid climate you may want to invest in a dehumidifier if you plan on making a ton of bombs. Make sure you seal your bombs in a dry container or shrink wrap them as soon as they are dry in humid climates. Round bombs aren\'t staying together- this is a real trick if you use kaolin clay in your recipe you may have better results. Never letting your molds touch when packing the bombs also helps. Scoop each of your molds full of combined bomb mixture and get them both heaping full and press them gently together, being careful not to twist or set them together off center. Once you have firmly pressed the molds together, and they were full enough not to touch after being packed together wait a moment and carefully begin to lift off one mold. Once one side is unmolded flip it over in your hand so the unmolded side is in your hand and gently lift off the remaining mold. Now press the bomb together with your hands and smooth the seam down slightly. Set on a soft towel to dry overnight