I know I have mentioned this a few times before in this thread in some way or another, but this is how I feel that most good stall teams end up looking like. I have looked through some other stall teams mentioned around and in the RMT forum, and the good one's follow this formula.
1. Primary Special Wall: All the teams I have seen have this feature, whether it be Blissey and Chansey or Clefable. It just seems necessary for the team's defensive backbone. I know that one can run a stall team without this kind of Pokemon in theory, checking special attackers through other Pokemon throughout the team, but I haven't seen that this generation yet.
2. Genesect Counter: As I just noted, most teams have a special wall like Blissey / Chansey or Clefable, while they are great walls, they fail to wall the special attacking monster that is Genesect. Most of the time this leads something like Heatran an automatic choice, however as Ajwf as demonstrated, other Genesect checks like Charizard-X are also viable in this slot.
3. Grass-type: Between their ability to check Pokemon like Breloom, Azumarill, Keldeo, a variety of Fighting-types, and ability to take on Rotom-W over and over again, Grass-types like Venusaur and Amoonguss pretty much always find their way onto stall teams this generation. Celebi and Roserade work similarly, but I haven't seen them used effectively yet. Gougeist, Trevant, and Ferrothorn all fill this niche but have a weakness to some of the Pokemon mentioned initially. I have seen a few stall teams without a Grass-type, but honestly they seem to be the exception rather than the norm.
4. Pinsir / Mamoswine counter: These 2 Pokemon have the smallest gap of counters as far as common physical threats go. The most common go to answer is Skarmory, but Rotom-W can work to similar effect. This Pokemon does not have to cover both of them at once, something that only checks one like Zapdos or Slowbro are fine, however they will have a weakness to one of these which will need to be covered in the next Pokemon.
5. A physical wall or check of some sort: Pretty much whatever you are not covering in the last Pokemon physical, should be covered here. It isn't going to be perfect, and it doesn't have to be, you have 1 more slot, but they should in a way complement each other and the Grass-type, covering most physical Pokemon at this stage. This Pokemon will vary depending on the team and what is needed, however Pokemon like Hippowdon, Gliscor, and Landorus-T are decent options.
6. Miscellaneous: Check / Glue / Spinner / Ect: This will usually the most varying Pokemon. It is basically what your team needs, whatever it is, it will usually tie up any lose Pokemon you have as threats, and make the team function better as a whole.