First off, you always have to put your Pokemon types into consideration for practically any team that you make. I find
Marriland's Team Builder to be a decent guideline in that respect. (General rule I like to use: NEVER use a team with 3 Pokemon weak to one type without 2 Pokemon with 4x-resistance / immunity to that type!)
Secondly, I've taken a step back to look at the metagame and see what kinds of attacks are necessary. Here's what I've compiled, so far:
-Physical Fighting attack to take on Blissey. If there's anything I've learned from my first standard team (which still had some success), it's that you really need this in order to deal with that pink bitch.
>>It would also help to have a Special Fighting attack (Aura Sphere, usually) or an Explosion as a backup plan. Every plan A MUST come with a plan B in terms of countering certain Pokemon; many battlers are already aware of this. "Hope for the best, plan for the worst."
-Special Ice attack for all the Dragons. Salamence is the main concern here, but it's worth noting that Garchomp has a lower base Special Defense than Defense.
>>Ice Shard works nicely as backup and fills the typical desire for a priority move, though I suppose Sucker Punch could work, too. More on that later.
-Special Electric attack for Gyarados. Self-explanatory, but make sure to scout for Electivire, first.
>>A physical Electric attack on something that can switch in is also an option. Stone Edge could also be useful.
-Special Grass attack for Swampert and the like. Grass Knot is usually preferred as it hits Tyranitar and Rhyperior harder than Energy Ball. (Swampert is hit for the same damage.)
>>A Special Water attack would also help, but the other needs above mostly cover those threats, too, as well as a...
-Ground attack. Earthquake and Earth Power are the only ones to really consider and is mainly specifically used for Heatran, though it also covers several other threats as noted above.
>>Again, if you're that worried about Heatran, go ahead and use a Water attack, as well.
-Special Fire attack for Steel Pokemon. Mainly for Bronzong and Forretress, but Skarmory is also hit hard, as well as Magnezone. Oh, how I wished that my first standard team had a Fire attack... :(
-Flying attack for Heracross; probably a Physical one as Heracross has a lower base Defense. This is a logical choice if you're using Gliscor as a Heracross counter--as most would say you should consider.
>>May be covered by the Fire attack, but most STAB users will have to worry about Stone Edge and Heatran has Close Combat to be concerned about.
-Dark attack for Cresselia and Ghosts. The likes of Tyranitar, Weavile, and Heracross will likely carry Pursuit/Crunch/Night Slash for this purpose. Others like Dugtrio and Spiritomb prefer Sucker Punch (which, as stated earlier, also fills the desire for a priority move). Others still also have access to Dark Pulse, if that suits your fancy.
>>Perhaps Shadow Ball could also help to this end. Several Pokemon like running the Shadow Ball/Hidden Power [Fighting] combo that nothing currently resists.
That's just what I believe is necessary for any team based on my experience and our Tier list. Other options to consider include:
-Passive forms of damage: Stealth Rock, Spikes, Sandstorm, and Hail are among this group. With stall-based teams seemingly on the rise (I have not battled in a while, I will admit.), this is becoming more of an attractive option. It also does its job of ruining Sash users. My first standard team, for example, employed Stealth Rock to damage opponents while forcing switches.
-Rapid Spin. If you use several Pokemon that are hindered by Spikes/Stealth Rock, a Spinner can come in handy. I, personally, prefer Donphan as a Spinner, but Starmie could also Spin effectively. As far as I'm concerned, Forretress just has too much to do... :(
...and that's all just on the Attacks side. Anything else I employ mainly depends on the type of team I use.
It's my opinion, though, and you don't necessarily need EVERYTHING I listed to succeed. Still, the more threats you can account for, the better your team will be IMO.
