I have not seen a random event in all the games I've played (about 20 untill now), even with the "more often" option.

I don't plan in having a random event each 10 turns, but maybe a minor event each 20-30 turns (for saying a number) could add some flavour...

So I will suggest some events (many of them taken from other games, of course...nobody is perfect).

- A visit of a trader with some special items...you will still need money for buying them...maybe the visit can stay for some turns...

- City events: A city can get improvements or troubles for X turns

   Growth (baby boom), Production, food (good harvesting), research boosts

   The same but the opposite: Growth (a disease) or even some deaths, Production (a failure that makes delay), food (bad harvesting), or research troubles

  These events should not be too rare. That would make heroes with Path of Governor a excuse to go to that city to lower the bad effects...

- Heroes: well...I'm no sure of this but heroes could get modifications in their stats also good or bad, because of accidents, diseases, a special training, or whaever idea you have, to modify a bit (+/- 1 or  2 points) to HP, dodge, attack, etc... nothing important, but a little of flavour.

- Units:

  Same than heroes: random modifications of their stats.

   Options of recruiting a rare unit (trolls, krills, or whatever you think) or not rare (guardkeepers, knights,...)

- Global Events. A lot of stuff here too.

   Same events that in the cities, but global...that would be rare...but possible

   Boost or Lowered mana income from a type of shards (for example x1.5 or x 0.5), like a planet alignement, or changes in the flowing of energies, whatever excuse

   Essence suddenly Flowing in a tile...

   Falling of a meteorite...Yeah, why not? It could affect 1 or more tiles...

Please, feel free to add more