gems and weapons.

Which weapons to use.

I would suggest don't go for weapons who help cavalry like naginata, And other spears. 

Best weapon combination is 3 basilisk ( weapons of catapults) and 1 sword ( weapon of infantry)  

Why not spears - they just help cavalry which we not use in attack cities. 

Basilisk gives additional bonus with catapults which will no doubt increase attack while attacking or defending attacks.)

Gems- 

Gems no one ever satisfied with their gems but you can distribute gems on heroes according to what you need from your heroes or according to enemies.
Normally keep gems 2 best attack weapons on best heroes,  best defence on defender hero.
And leave one hero with minimum attack and defence to die first in tower or attack city.
To get suggestion on newer gems and many more click here 

Apple gems tips:
Apple Gem = 6* gem + 99gc

----------------------------

Dual-Attribute Apple Gem =

5* dual-attribute gem +
300 soul shards +
300 gem fragments +
399gc (300 = 6*d.a. + 99 = d.a. Apple)

***OR***

3x6* gems +
Enchantment Scroll (cost 1000 soul shards) +
99gc
(This process can be performed in two different approaches--make Apple first, then merge with 2x6* and scroll to make d.a. Apple; or after, using 3x6* and scroll to make attribute gem, then 99gc to d.a. Apple)

~~~use first method if you have more gem frags and gold, use second method if you have more shards or no 5* D.A. Gem~~~