on older manual trannys, I double clutch most of the time when downshifting. Clutch in, put in nuteral, clutch back out and rev engine, clutch back in and put it in gear. That brings the input shaft and gear cluster (counter gear?) up to higher speed so it is more closely matched to what it will be when you put it back into the lower gear. Smaller lightweight trannys don't grind as easy as the older bigger ones. Trick trannys, I almost always double clutch when downshifting.
