City Development

Things I suggest to have your attention on :

1. Keep level. Try to get your keep up as fast as you can at least lvl 30. Do not build too many troops under troop tier 10 or 11 - that won't really help in defense or attack in player versus player fights. Don’t worry, you don't need to have everything up to keep level to develop further.
2. Academy research ( advancement, military, defense and alliance help buttons, after that try to research things that will be for your type of game play ).
3. Your in city resource tiles ( farms, sawmills, quarries and mines). At keep level 28-30, try to have all your in city resource tiles at level 27 ( ideally ). Best is to have balance, food not so much, army camp can be 2-3 ( you can research training capacity, so it is not so important to have many)

Gathering. Have your gathering teams do their job when you are offline or know you won't have time for being online.
For gathering you want to have Queen Jindeok and add to her 3 gathering books ( remember to add skill books starting from low levels, only then add lvl 4 ).
If you cannot have Queen Jindeok then Constance I , Lady Lucy and some other purple generals can help you with that until you get Jindeok.

Joining rally . Join as many rallies as you can - that gives you additional bonuses , especially joining event bosses ( gives great resources ). Have your march speed horn on, research march speed in academy too. If you have problems with having slow march, message me!
My favorite combinations for joining monster rally would be :
Theodora + Nathanael Greene = Theodora gives bonus drops, while Greene gives stamina reduction .
Baibars + Greene = Baibars gives bonus drop, Greene - stamina reduction.
Great to have general equipped with a double drop ring for hunting monsters ( but only main general, assistants gear does not work )

Short story about generals - any general you are developing : only the main general needs to be top of the top ( best quality, best equipment). Assistant generals are there mostly because of their skill books and speciality. Do not need to ascend them or cultivate - that will not add anything to battle. Only skill books and specialties that can be developed after general reach level 25.