When diving with my usual buddy in some of our often-visited sites, the "plan your dive" part can be as simple as two-word conversation: "Clockwise?" "Sure." In that, we've decided all the variables of the dive. It sets the navigation plan, which sets the profile, which determines our timings and gas plan... Basically, it's just about like those "let's pick it up at step 89-5.3(a)" lines that you hear when you're watching rocket launches -- as long as everyone has the proverbial manual, you may not need to actually read it aloud.
Then there are dives like we did in Bonaire. For those, the diving was flexible enough that a precise plan was not necessary. Obviously, that's not to say there weren't *constraints* on the dives (deepest part first, observe MODs, and so on). The actual execution of the dive plan had to remain flexible. If we started deeper to see something, the ascend-and-return pressure could be lower, as that would alter the ratio of the rates of pressure consumption between the deep out and shallow return legs. If there was less current, the ascend-and-return pressure would be higher, as there'd be less current-assist on the return leg. There was sometimes even an alternate drift plan for compatible sites; if the current was mild, do the out-and-return dive, but if it's too much, drop the return leg and make it a strict multilevel drift.
For a relatively inexperienced buddy pair, it may be wise to more explicitly specify the dive plan ahead of time. Perhaps put a hard limit of 60 or 70 feet on the deep part. Maybe set 1750 psi as an ascend-and-return pressure, as evaluating everything during the dive may not be something at which the buddies have enough experience. On the other hand, if your skills and experience are sufficient, you can observe the conditions, monitor yourself and your fellow divers, and use a more dynamic dive plan.
When it comes to specifics, if there are any goals (photography, exploration, training, or what-have-you), those need to be discussed in the plans. It is never a good idea to pair an explorer-style "gotta see it all" diver with a macro photographer. On the other hand, for a solo dive in quiescent, divers-only freshwater with not a single goal other than to just be underwater (okay, and return safely), I'm perfectly comfortable to have a dive plan that consists of nothing but a "Whatever" (with all the constraints implied).
(By the way, the page that all too often gets left off dive plans is the one titled "Contingencies". It doesn't matter how implicit or explicit the primary plan is if the dive's going to end up in the next issue of Alert Diver if anything goes wrong.)
Oh, and as for the cute little bug... If you're using Firefox, you can right-click it and choose "Block images from [...]" to make it go away. That'll block everything from the site on which the image is hosted, but looking at the obscure URL, that's not likely to impact your browsing. :biggrin: