[HGSS] Pokemon Team Held Items

Ok, so my Pokemon team is almost done, except for held items. Which held items would be best for each, or should they remain the same?
Luxray (female)
Level 100
Moves:
Crunch
Discharge
Spark
Thunder
Current held item: Magnet

Infernape (male)
Level 100
Moves:
Grass Knot
Close Combat
Ember
Poison Jab
Current held item: Black Belt

Charizard (female)
Level 100
Moves:
Dragon Claw
Heat Wave
Flamethrower
Air Slash
Current held item: Flame Plate

Charizard (male)
Level 100
Moves:
Flamethrower
Rock Slide
Dragon Pulse
Overheat
Current held item: None
(Has higher stats than the other Charizard)

Froslass (female)
Level 100
Moves:
Crunch
Ice Beam
Thunder
Blizzard
Current held item: Never Melt Ice

Mewtwo (None)
Level 100
Moves:
Aura Sphere
Shadow Ball
Psychic
Water Pulse
Current held item: Odd Incense

The team is used for regular battling for fun, and also I use them to help level up the other Pokemon. I'd like to give them the best held items for each, so which held items should I use?