A good tip demonstrated by example, than I'll explain it a little bit:
If not A than B
Notice that the two necessary conditions are the same, as in, they are both positive and not negated. This means that no matter what one of these will have to be IN. So, when I create my diagram, I will write in the IN column, "B/A" reminding myself that I always need at least one of them.
If A than not B
Again, notice how our two necessary conditions are the same, as in, they are both negative and not positive. Thus, we know that we are going to need one of these in our OUT column. So, again, like in the above example, I will write in my OUT column, "~B/~A" reminding myself that one of these needs to be out.
This really helps in remembering what variables you need to be keeping an eye on. Furthermore, for those questions of, "whats the maximum/minimum that could be IN/OUT" you can refer back to these and see that you will need one of these no matter what, and than do a hypothetical with them and get an answer pretty damn fast.
I love IN/OUT games. I find them to be very easy. This is subjective, but I hope we get 2, maybe even 3 in June!