Situational awareness in and around the Stack is very important for a couple of obvious reasons. First, it is necessary for you to to know where you are within the stack in order to give out useful position reports which helps the others in your flight improve their situational awareness and help affect a quicker, more efficient rendezvous. Secondly, it helps to keep you from running into someone else in your flight!
First, let's make sure that we all are perfectly clear on what the stack is and what it's dimensions are. It is a cylindrical space that is 5nm in diameter, starts at 2000' MSL and extends up to and includes 5000' MSL, the center of which is located directly off the port beam of the boat. 6000' MSL and above belongs to tankers and Case III approaches. I think that from a practical matter, we should plan to use the highest level, 5000', for the first flight that is scheduled to depart for their first waypoint and each subsequently scheduled flight will rondezvous in the next level below. This may help deconflict traffic departing the stack.
The whole purpose of the stack is to help deconflict various flights and aid in getting those flights joined up and on their way. Knowing this, you can see where it might be pretty important to have some fairly ridgid rules while operating in the stack. The first one is to maintain your altitude as close to assigned as possible. That gives you and others in the next level up or down, a thousand feet of clearance. The second is to maintain the airspeed that is specified for the stack, in this case, 250 knots indicated. This will help keep you from running into someone from behind, or getting run into yourself provided everyone is maintaining their speed. So, the only way to make a rendezvous with someone that is way out in front of you is to lead the guy by quite a bit and cut through the circle to gain on him. I always try (TRY being the operative word here) to remember to engage my Auto Throttle Control at 250 kts and engage my autopilot's BARALT function in order to hold my assigned altitude. Having done this, all I need do is roll the plane into a steeper turn in order to cut across the circle to catch up with the plane I am trying to join up with.