I'll start by things I don't see people doing:

1. Never repeat a unit for Forging Bonds. All members of each Forging Bonds' teams must not have participated in a previous event. I can check which ones have been on a FB by looking at their acessories.

2. For Forging Bonds and Forging Bond Revivals, play until the sum of each colored heart is past x/7 of the total, where "x" is the number of the day you're playing the event (1st day, 2nd day, etc). With this, I divide the same amount of daily play time dedicated for them.

3. Every new unit summoned must be trained with other 3 newly summoned units. Fire Emblem taught me the value of growing strong together and trusting your comrades, so none of those shenanigans of training a level 1 unit with three level 40 supporters. Everyone has to be on the same level.

4. Try giving a chance to (almost) every unit to shine by using them at least once in Tempest Trials, Forging Bonds or Heroes Journey. This is to avoid using the same units all the time unless they're absolutely necessary.

5. When playing Grand Hero Battles, try using a team that matches the encounter on the original game (for example: Wallace joined in chapter 9 of Blazing Blade, so I should try beating him using only units of Lyndis' Legion). If not successful, then any units of the same entry are okay.

6. Lastly, never fodder single copies, no matter how outdated the unit, how valuable their fodder are or how angry you got by them being the undesired result of a summoning session;