So I've been using Charizard on a team for several months now, so I figured I'd make a miniature guide. Keep in mind that I am by no means an expert and this is just what I've learned from using Charizard.
1. Don't use Charizard- I love Charizard, and I think most of this board know that, but I'll be honest, Charizard is terrible in OU. Unless you particularly want to use Charizard (which is my case), don't use it. It really isn't a good choice if you are just filling a spot on your team
2. Physical Charizard is awful- BellyZard worked a few gens ago when OU wasn't as fast or as powerful. Besides, Darmanitan knows Belly Drum, is almost as fast, and has waaay better attack.It doesn't work anymore. In regards to Swords Dance and Dragon Dance, Charizard has NO niche at all. Not even a small one. Base 84 Atk is usable, but there is really no reason or benefit to using it.
3. Only use SP Charizard on a Sun Team- SP may not be a great ability, but it does give Charizard a niche. With Solar Power, Charizard can OHKO or 2HKO nearly everything in OU without having to take a turn to boost.. And you can remedy the damage with leftovers if you like.
4. Keep Stealth Rock away- Charizard isn't slow by any means, but like most fire types, it's not THAT fast either. That means you are going to want to switch out when something like Terrakion switches in. So you should either use an Espeon or a rapid spinner. I prefer Espeon because it can pass Calm Mind boosts to aid in a sweep. It also helps that it's my 2nd favorite and my signature pokemon.
5. Charizard can take a Neutral hit- People love to make Charizard out as some super frail mon with horrible typing, but the truth is that it has some handy resistances and can take a neutral hit. That means if you are late in the game and someone brings in an Alakazam, don't be afraid to let your Charizard take a hit (assuming it has high health)
6. If you are using a non-choice set, maximize your coverage- Charizard has the benefit of being a Fire type that learns Dragon type moves and Focus Blast. It's not Reshiram, who gets STAB on both, but having such perfect coverage is very useful so that you don't have to switch out for anything other than speed when SR is around. If you aren't worried about Heatran, you could forgo Focus Blast. The other critical move to carry is Solar Beam or HP Grass. With that, you can counter 2 of it's 3 weaknesses with a 100% accurate SE hit. Even if you're ARE using a choice set, having good coverage is good if you are predicting a switch. --- Not changing this sig until we get a new main series Tales game released on a Nintendo console in the US Dictator of the Zelda Wii U Board