I have my bobbin warning set on the lowest setting but still stitch past it if I estimate there will be enough for the particular colour I'm stitching, in embroidery mode, or seam etc I'm doing, in sewing mode. If you always leave the setting the same you will know from experience how much thread you have left, but of course the amount will vary depending on the thickness of the thread you are using.
If it has bobbin thread on it I use that, on the vertical spool pin, for either basting fabric to the hoop, or for basting that I do in ordinary sewing. If it's another type of thread I use that for testing out different stitches and tensions when I am planning a sewing project, - either in the bobbin case or on top - or use that for basting as well.
I have 6 different colour bobbins - yes apart from the clear ones the others are from China (about £2 for 25 in a case) - so I know what type of thread is on which bobbin, though I am planning on employing a marking system given there are more than 6 combinations of threads and sizes! I've never had a problem using any bobbins including the Chinese ones, yet! Except - a couple of the centres are just that little bit too narrow to fit over the bobbin winding spindle - then I just wind them on another machine.
"Life may not be the party we hoped for, but while we're here we should dance". Anon