Here is the summation.

When I win, I take 1/3 of the win money and pocket it, cash it and will not in any way whatsoever use it.  I take another 1/3 of the win money and increase my Bankroll with it.  I take the remaining 1/3rd of the win money and keep it as a reserve if I lose my bankroll I am playing with and still desire to play longer. 

You can do it with any amount of win.  Say you buy in with $600.00 and get up to $1,800.00.  Take $400 and pocket it.  Increase your Bankroll to $1,000.00 and put the other $400 in your pocket as a backup bankroll. 

Say you won another $1,000.00.  Take $350.00 and make your bankroll $1,350.00.  Take another $350.00 and put it with the $400.00 and that makes $750.00 you can't touch.  Take the other $300.00 and put it with the reserve bankroll you have of $400 making it now $700.00.

For me, I get the piece of mind, that I always have another chance if I lose and still want to keep playing.  I have something from my win money already 'locked up' and cannot be touched.  I have a slightly bigger bankroll.  When I do these things, it stops me from playing the way I used to with win money, and seldom holding on to it when things turned ugly. 

All I know for me and some others, compiling the win money into your bankroll sitting on the table, only makes it subjected to larger bets and being lost easier than it does without some kind of plan. 

Do it with any amount of win money, adjust it for your own psychological well being.  To me and most I speak with, it is easier to walk away after winning, when you know you have really tried to win more and maybe one more shot or another round at a table after a meal or a break, etc.  Maybe you can win money and stack it up in front of you and value it properly, but for most players it makes them play a bit more recklessly and dangerously then when they initially sat down with XYZ bankroll.

For me, I am satisfied with the way it works out when I do some kind of plan as I mentioned here.  When I just throw the winnings into the stack in front of me, I have to attempt calculations at how much for this and how much I should cash out 'later', etc.  If I put all my winning  into my pocket and employ 'attempted' willpower, there is no reward and satisfaction for the instant time, while sitting there playing.  If I divide it up as I go along, I have clearer mind and gives me a psychological advantage.