I don't do any kind of shave count whatsoever. I just use the acronym TSD...when any blade starts to Tug, Scrape or do Damage it goes, no matter how many shaves it's given me (or not given me). It's a rule o' thumb that serves me well.
The die is a good idea. I just start the week with a fresh blade on Sunday if I remember. Usually about Wednesday or Thursday I change it before the shave. If I forget for a day or so it's not a big deal. If it's a poor shave early in the week I change it early.
I toss a blade Friday, meaning I start my weekend Friday night or saturday morning with a fresh blade. Then I shave every day until next Friday with that blade. Works wonderfully.
I toss after 2 shaves of 2 passes regardless of which blade I use. At that rate I'm spending around a nickle per blade per shave, probably the least expensive personal hygiene thing I do for or to myself. I don't understand the intense interest in the number of shaves per blade, it isn't worth the fuss at the typical cost of blades. To me it's much more important to have a fresh blade when I shave than to save a couple of pennies a week.
3 shaves with 3 passes. With my go to blade (Astra SP's) that's .0333 cents per shave. For me I don't think it is worth it to push for anything more. Now when I finally break into my Personna 74's I will push those to see how far I can go compared to others who claim to get 20+.
I pretty much also follow @gorgo2's rule of thumb. It saves me from worrying how many passes I put on a blade or when it's time to change. At the price for a DE blade, I figure it all works out in the end anyway.
Typically I toss after 3 two-pass shaves. I once pushed a Voskhod to six, but did not want to push it, even though the shave was still ok. If a blade tugs too much, I toss it. When in doubt, I toss it.
No need to push anything, I agree that far But I can't figure out why toss something that works, just because it's cheap? I mean, in my case, when I get 6-7 great shaves on my best blades, why toss it by rule of thumb after 2-3 shaves when I know I get twice with same performance? Does not compute. It's not like I'm pushing and enduring pain between shave 4-6, I can literally not tell if I'm on shave 4 or it it's a new fresh blade.
If I do not keep the track of shaves, I can easily use a blade more than 10 times. Because I have bought hundreds of blades, I started tossing them after a few shaves. By the way, the first shave is not necessarily the most enjoyable. The fifth shave can be better than the second one. There are so many subjective variables when it comes to shaving, that not everything can be explained scientifically.
