Bravery is much easier to increase in this mod compared to the base game. Early game, money is tight enough I don't reject anyone. Later on, I'll likely reject based on PSI strength than anything else.
Commendations give boosts that aren't counted against the cap (you can have more than 100 bravery this way), but they do count for requirements for trainings and enhancements.
Besides using interceptions (Bases/Embassies are great for this), Healing is a great way in combat. Just make the low-bravery agent the preferred medic, and it'll go up on its own.
One other way is using the garrote and surfboard weapons. Neither weapon is great, and you only can get surfboards on the surfs up mission.
It's really good to maximize your bravery because the Kukri is an amazing weapon due to its bravery scaling. At 140 bravery, you have +59 damage from bravery alone.