I would run Top down - shallowest first, but other combinations can work well. Have seen it done sideways which was quite clear but would be more inclined to stick with top down.
It makes little difference provided that YOU know where your stops are during the ascent.
IANTD have just launched a flexible runtime mini-slate that is very good and which store well in a set of wetnotes. With wrist space being at a premium they are small enough to stow easily and being flexible they don't get in the way.
Flexible IANTD UK Decompression Runtime Planner - £4.99 : IANTD UK, The Leaders in Diver Education