If you're crafting without knowing the outcome of what you're doing, you're doing it wrong. I got that from "using Synth until I'll one turn away from finishing."

Have 360 Craftsmanship and eat CP food. Inner Quiest>Steady Hand II>Hasty Touch to 20/80 while using ToTT on every good. Masters Mend II. Repeat to 30/80.

Now, have you landed at least 8 touches? Good. Great Strides > SHI > Ingenuity > Byregots > Standard Synth x2 and you've just gone 100%/100%.

Did you land less than 8 touches but still have more than 130 CP? Manipulation/Mend and use more touches to get to at least 8.

Basically, the idea is that you have at least 11 80% chances to land Touch, and you need a 75% success rate. Of course, odds are you'll have gotten enough Goods to get more durability or you'll have had enough left over CP to use a 100% touch a few times to get you to where you need to be.