Whenever you start a new project make a project page in your bullet journal. It will save you a lot of grief in the future, trust me! I do this regardless of the kind of project I am doing. I do find it is most useful for my yarn and crochet projects though.
On this page include pertinent information like where you sourced the pattern or tutorial, the supplies you used, changes you have made, and your start and end dates.
If you ever have to put the project aside, you will have all the information you need when you pick the project back up. A page like this is also useful if you ever want to do the same project again. You can also include sketches, yarn swatches, or fabric swatches.
Think of this as building up a reference library of projects that you can use again and again, and even pass on to others.