When do you change your blades? I've used my blade 3 times and it's still just as sharp.
+1 - Even if you notice problems mid-shave, change it right away. Usually I change my blades on Sunday or Monday regardless of how the blade is doing and mid-week if needed.As soon as I get any kind of negative feedback from the blade: tugging, rough feeling, etc.
As soon as I get any kind of negative feedback from the blade: tugging, rough feeling, etc. However, even with a blade that is performing well, I will toss it after 3 shaves and not try to press my luck.
I generally go until the shave quality declines or seven shaves, whichever comes first.