Strategies are important if you want to beat your friend's Pokémon team. Here are some helpful tips for those who want to build strong teams.

Okay, let's say, you send out a Blastoise. So your opponent thinks, "Easy." and he sends out a Venusaur. He thinks that he has the advantage since Grass can defeat Water. But what he doesn't know is that Ice attacks can freeze Grass.

Yes. You can use TM's to teach Blastoise ice attacks. So...it'd be like :

VENUSAUR is gaining sunlight!
BLASTOISE used Ice Beam!

And POW! Venusaur has half HP gone(or all of them).

It's good to surprise your opponents with TMs. =) Like...let's say, Persian between a Pidgeot.

PERSIAN used SLASH!
PIDGEOT used MIRROR MOVE! PIDGEOT used SLASH!
PERSIAN used THUNDER!
PIDGEOT fainted!

Yes, and your opponent would be totally devastated. ^_~ Because Persian can learn TM25, which is Thunder. =)

Zapdos, Articuno & Moltres are good fighters, but if you chose them all, your team might consist of half flying Pokémon, so they can all be taken down by any Ice or Electric Pokémon.

Everybody(well, maybe not everybody, but -some-), may use Mewtwo as their "strongest" Pokémon, but not everybody knows that -shh- Mewtwo can be taken down by one special yet neglected Pokémon. What is it?

No, it's not Alakazam.

It's...Parasect. Yes, even though in people's eyes, Parasect is considered lousy and usually chucked in the PC when caught in the Safari Zone. Parasect has very good attributes in every stats, but only in speed...he's weak there. So in battles, your Parasect might get a little attack first before Parasect can do Spore, Growth and Leech Life.

Never carry two or more Pokémon on your bench that can be wiped out by the same Pokémon, i.e. Pidgeot, Gyarados and Dragonite can be taken down with one blast of Thunder by Jolteon.

Usually when the other person's Pokémon is beating up your Pokémon, for instance, let's say...your Raichu is being beaten up by Dugtrio, and half of Raichu's HP is gone and none of his attacks work since ground isn't affected by electric at all. So you might be tempted to switch to any water Pokémon, but by switching, you allow the Dugtrio to get the first move on your Blastoise.

Having the starter Pokémon on your bench are...well...not so good. Blastoise, Charizard and Venusaur are good, but you've been using them like, for almost the rest of your journey. Not to mention if you bring them to Elite Four, and you have packed a Zapdos, and Articuno, you won't be using much of them. For instance, my Charizard. Ever since I got Zapdos, I kept using it against Lorelei's water Pokémon, and I only use Charizard like...twice. The first time was to defeat Lorelei's Jynx, and Gary's Exeggutor. That was all.

If you have Venusaur, you won't be using him much either. If you have Blastoise, you won't use much of him either, since with Zapdos and Articuno(or Moltres), you barely need the starter Pokémon because Zapdos and Articuno can take down almost all of the Elite Four and Gary's Pokémon.

Eventually, I keep changing teams. My first was only...Zapdos, Charizard and Articuno. Then my second was Mewtwo, Dugtrio, Charizard, Zapdos, Cloyster, and Parasect. My third was pretty much the same as the second one except with Dewgong. The fourth one was with Haunter, Lapras, Zapdos, Arcanine, and some I forgot. Now the one I use are Aerodactyl, Jolteon, Lapras, Arcanine, Mewtwo and Parasect. And all of them have parts in defeating Gary each.

Some suggestion teams are Mewtwo, Parasect, Arcanine, Cloyster, Hitmonlee and Jolteon; Electrode, Blastoise, Starmie, Tangela, Mewtwo and Ninetales. However my dream team is usually one that must contain a Pokémon that can FLY and a Pokémon that can SURF. ^_^

Those are just some suggestions for powerful and strong teams. You can play around and see which one you like, and maybe settle down with that. =)

Good luck!