I will tell you how I do it right or who knows
When I rack the beer I have about a cup of beer left in on top of the yeast cake. I shake the stuffing out of the fermenter swirling it to get the whole yeast cake broke up and in solution with the little bit of beer I had to leave in the fermenter.
I take 4 pint jars that I have had boiled to sterilize and fill them right up to the top and cap them and toss them in the fridge. I suppose I could get 5 pints but 4 pints works for me.
On brew day I pull the yeast out of the fridge and let it warm up to room temp while I am brewing and when I pitch the beer I shake the heck out of the pint jar and then dump it in.
I started a brew log this year to help me keep track of things I have done that work and do not work. I keep track of all my yeast in that as well. I figure 4 generations and then I will buy more meaning I get 16 batches out of one pouch of yeast. I know I can get more but this works plenty good for me