I like to stitch by colours in the area of the hoop. I generally start stitching with the colour which has the most visible chart symbol so it is obvious to see - this really depends of the symbols that are around, but I just choose the one that catches my eyes. I have less chances to forget a stitch or to misplace it. When a zone contains similar colours, I will stitch the darkest one and then the lightest one and then go on with the intermediary colours, having yet various points of references. This isn’t a faster method, but an easier one for me so it reduces the time undoing wrong stitches.