This the first time I've done this so forgive me for any mistakes here and there.
Anyways, despite the presence of Charizard and Sawsbuck I'm surprised there aren't a lot of RMT of Sun teams with them. So I thought I'd share my team here and hopefully gain some advice on how to improve it.
Jumpluff @ Heat Rock
Chlorophyll
Jolly (+Speed, -SpA.)
248 HP / 44 Def / 216 Speed
~Sleep Powder
~Sunny Day
~U-turn
~Memento
The main set up poke for Sun, Jolly nature so U-turn isn't weakened and now you have one of the faster pokes in the tier. In battle just Sleep Powder then Sunny Day and proceed to U-turn to a suitable counter. The only move I haven't found that useful is Memento because I don't like the idea of sacking it on anything. Though it might be useful if a Magmortar is making too much of a sweep on this team.
Probopass @ Air Balloon
Magnet Pull
Modest (+ SpA, - Atk)
252 HP / 4 Def / 252 Sp.A
~Stealth Rock
~Power Gem
~Earth Power
~Volt Switch
Probopass is his name and setting up stealth rocks is his game. Aside from the rocks Probopass is also there to block certain threats, namely Swellow. I chose Magnet Pull as his ability to take out the few steel types in the NU, it's not that great I suppose but guaranteeing to an opponent's Steel type is always nice. Max out his Special Attack so he can actually deal some damage and he's bulky enough for what he needs to do.
Wartortle @ Eviolite
Torrent
Calm (+SpD, -Atk)
252 HP / 4 Def / 252 SpD
~Rapid Spin
~Scald
~Aqua Ring
~Protect
Well when you have a Charizard you have to have a Rapid Spinner and Wartortle is the only NU spinner that isn't weak to rocks. Scald is the default attack, and AR + Pro give a pseudo Leftovers recovery. He makes a decent special wall, but overall he's just meant to spin.
Charizard @ Choice Specs
Solar Power
Timid (+Speed, -Atk)
252 SpA / 4 SpD / 252 Speed
~Flamethrower / Heat Wave
~Air Slash
~Hidden Power Ice
~Solarbeam
The first reason I made this team and I love it, Charizard is So Powerful. I use Flamethrower instead of Fire Blast for it's accuracy and for the fact that with Solar Power, Specs, and Sun Fire Blast would only be overkill. I have thought about using Heat Wave for some extra power against some tougher Special Walls but I haven't tested that out yet. All the rest of the moves are for coverage but Flamethrower is so powerful they're hardly ever used.
Sawsbuck @ Lum Berry
Chlorophyll
Adamant (+Atk, -SpA)
4 HP / 252 Atk / 252 Speed
~Swords Dance
~Frustration
~Horn Leech
~Jump Kick
The second reason for this team and another awesome powerhouse. Under the sun this poke is so fast it can out pace Scarfers easily and even outside of sun it's still has decent speed. Swords Dance to set up, Frustration/Return for a really powerful STAB, Horn Leech for STAB and recovery, and Jump Kick for coverage. Lum Berry is used to make sure he isn't Burned or Para before he can set up.
Exeggutor @ Heat Rock
Chlorophyll
Modest (+SpA, -Atk)
4 Def / 252 SpA / 252 Speed
~Sunny Day
~Solarbeam
~Hidden Power Fire
~Psyshock
The second poke that can set up sun and really good sweeper under it. Solarbeam for STAB, HP fire for Coverage, and Psyshock for those some of those Special Walls.
Anyways, despite the presence of Charizard and Sawsbuck I'm surprised there aren't a lot of RMT of Sun teams with them. So I thought I'd share my team here and hopefully gain some advice on how to improve it.

Jumpluff @ Heat Rock
Chlorophyll
Jolly (+Speed, -SpA.)
248 HP / 44 Def / 216 Speed
~Sleep Powder
~Sunny Day
~U-turn
~Memento
The main set up poke for Sun, Jolly nature so U-turn isn't weakened and now you have one of the faster pokes in the tier. In battle just Sleep Powder then Sunny Day and proceed to U-turn to a suitable counter. The only move I haven't found that useful is Memento because I don't like the idea of sacking it on anything. Though it might be useful if a Magmortar is making too much of a sweep on this team.

Probopass @ Air Balloon
Magnet Pull
Modest (+ SpA, - Atk)
252 HP / 4 Def / 252 Sp.A
~Stealth Rock
~Power Gem
~Earth Power
~Volt Switch
Probopass is his name and setting up stealth rocks is his game. Aside from the rocks Probopass is also there to block certain threats, namely Swellow. I chose Magnet Pull as his ability to take out the few steel types in the NU, it's not that great I suppose but guaranteeing to an opponent's Steel type is always nice. Max out his Special Attack so he can actually deal some damage and he's bulky enough for what he needs to do.

Wartortle @ Eviolite
Torrent
Calm (+SpD, -Atk)
252 HP / 4 Def / 252 SpD
~Rapid Spin
~Scald
~Aqua Ring
~Protect
Well when you have a Charizard you have to have a Rapid Spinner and Wartortle is the only NU spinner that isn't weak to rocks. Scald is the default attack, and AR + Pro give a pseudo Leftovers recovery. He makes a decent special wall, but overall he's just meant to spin.

Charizard @ Choice Specs
Solar Power
Timid (+Speed, -Atk)
252 SpA / 4 SpD / 252 Speed
~Flamethrower / Heat Wave
~Air Slash
~Hidden Power Ice
~Solarbeam
The first reason I made this team and I love it, Charizard is So Powerful. I use Flamethrower instead of Fire Blast for it's accuracy and for the fact that with Solar Power, Specs, and Sun Fire Blast would only be overkill. I have thought about using Heat Wave for some extra power against some tougher Special Walls but I haven't tested that out yet. All the rest of the moves are for coverage but Flamethrower is so powerful they're hardly ever used.

Sawsbuck @ Lum Berry
Chlorophyll
Adamant (+Atk, -SpA)
4 HP / 252 Atk / 252 Speed
~Swords Dance
~Frustration
~Horn Leech
~Jump Kick
The second reason for this team and another awesome powerhouse. Under the sun this poke is so fast it can out pace Scarfers easily and even outside of sun it's still has decent speed. Swords Dance to set up, Frustration/Return for a really powerful STAB, Horn Leech for STAB and recovery, and Jump Kick for coverage. Lum Berry is used to make sure he isn't Burned or Para before he can set up.

Exeggutor @ Heat Rock
Chlorophyll
Modest (+SpA, -Atk)
4 Def / 252 SpA / 252 Speed
~Sunny Day
~Solarbeam
~Hidden Power Fire
~Psyshock
The second poke that can set up sun and really good sweeper under it. Solarbeam for STAB, HP fire for Coverage, and Psyshock for those some of those Special Walls.