[Padowan]

I have one of those larger flip up slates, and on the bottom slate (the largest one) I have indented a grid using some deft work with a soltering iron, this gives me lines that don't rub off, I then write all my schedules for any half decent dive I do. All I write down is the runtime at the particular stop, working from deep on the left, to shallow on the right, so it might look something like this...

.. 55 50 -- -- 36 30 27 24 21 18 15 12 09 06 03 00
P. -- 20 -- -- -- -- 23 24 25 26 27 29 32 43 -- 49
+D 20 -- -- -- -- 23 24 25 26 27 29 32 35 48 -- 54
+T -- 25 -- -- -- -- 28 29 30 31 33 36 39 54 -- 60
OC -- 20 -- -- -- -- -- 21 24 25 26 28 31 36 42 45
B. -- 10 -- -- -- -- -- -- -- -- -- 14 15 16 -- 25

P = Plan
+D = More depth, usually I do +5 for the planned bottom time
+T = Extra time at depth, usually 5 minutes
OC = dive plan, OC ascent
B = Bailout (for example descend and don't find wreck), usually half the planned bottom time

I used to have a (-G) column which was when I was on OC, and was a lost deco gas plan, but now I'm on the box, I have the OC row which is for the depth and time as planned and doing the ascent on whatever OC gasses I'm carrying

The depth labels are not permanent, so I write in whatever depths I need either for bottom depth variations and stop depths...

This is a flexible arrangement and it works for me.