These are the recipes and calculated oxide chemistries of two pottery glazes (as shown in my account at insight-live.com): The original problem recipe and an adjustment to fix it. Recipe #1 sources boron from a soluble material and three plastic materials are combined to increase drying shrinkage enough to cause cracking when drying (and thus crawling). Recipe #2 solves these problems while producing the same chemistry. It sources boron from two frits (one having almost no Al2O3) whose ratio to each other can be altered to supply more or less Al2O3 to the melt. That enables removing two of the plastics: Ball clay and Gerstley Borate. The remaining 20% EPK is perfect to create a creamy slurry that suspends, applies and dries well.
You will see examples of replacing unavailable materials (especially frits), fixing various issues (e.g. running, crazing, settling), making them melt more, adjusting matteness, etc. Insight-Live has an extensive help system (the round blue icon on the left) that also deals with fixing real-world problems and understanding glazes and clay bodies.