I usually stitch by colors. I start with a single color and stitch everything in that color, and then I skip to the next one. But, I've noticed that many people start from the top and stitch row by row downwards. I would like to try that technique, but not sure how to do so. Should I end the thread or leave it hanging until I need it again? What's the rule of thumb to end a thread vs leave it hanging? Any advice you can give would be greatly appreciated.
I think you are referring to the Parking method, where you pull the thread through in the next place it will be used, as though you going to make the first pass of the stitch, and leave it there, while also covering up the thread on the back with stitches. I personally haven't used that technique at all, but I have been told it works fantastic, especially large projects. I'm just not sure my mind works in a way compatible with that.
Depending on the project, I sometimes start in the middle, or top left corner when I need to get it exactly centered. I try to work in color areas; for instance, in the one I am working on now, the center panel has a castle, with trees/greenery and a lake, surrounded by border. The castle was center, so I began there, and as there were 20 color changes in 5-6 inches, I would work all of one color before moving to the next, trying to go from light to dark. But also, I would break that up into manageable sections; I did the outside right wall and its two towers, doing all colors (my design has backstitching, so I let that help define my areas), then moved to the next section and its towers, etc. Then to the first row of trees, then the lake, then the trees in the foreground. Getting a complete piece of the picture done (the darker set of trees, the lake reflecting the castle) are small accomplishments that make the whole seem to go faster.
Now, when I begin my SQ Lady w/Unicorn, I am not sure how I'll work it. I will start top left, for sure, but as you've got to get to the middle to have smaller areas of similar color, I don't know if I'll go page by page, top to bottom, left to right, or what. I use scroll frames, so whatever method will keep me from having to adjust that any more than necessary. I may have some trial and error before I hit my pace, and since this will be the biggest I have worked on, that might take me some time. Or I may lose my mind long before I hit my pace!
I don't spend a lot of time worrying about how neat the back is; I don't know if that's good or bad, but I've been doing this and framing them for going on 20 years, and haven't really had any issues with a "messy" back. I understand the need to keep a huge project neat, unbulky, but I usually go back when done and trim more lose threads and let it go at that. There are no knots (except the ones I don't see, then wonder how my new section of thread got so short so quick!), but once I am sure those are well-incorporated, I try to trim them out. It looks a little messy when I'm done, but to feel it, it's not too nubby, I guess might be the right word.
Not sure if that helped, or if you're even still awake! I can rattle on when talking about my other favorite subject (the first being books)....