F2P Currency tips!! (in a sense)

If you have the 4* and 5* and you don't have much to go around in terms of skills but you have the feathers to promote your 4* marth to 5* here's a lil guideline that I follow for my dupes in a situation like this.

Level up your 5* put your skills you want on her, I'd prefer the usual L&D with Desperation and Threaten Defense or Hone Defense to pair up along side Ephraim with Hone Speed and Fury Desperation Nino. For support and Special Ardent Sacrifice and Dragon Fang is what I'd go with since I feel like Luna or something might not be as effective for her Role on my team, plus super hard hits.

-Put most of your skills in the 4* since you'll be able to get twice as much sp from her after promotion.
-Inherit the other few on the 5* version and level her till she gets all the skills you can with her (for my build I'd put the ones harder on SP like most usually the A and B passives besides the small stat increase ones in the A passives).
-Once you promote your 4* don't unlock the Legendary or 5* Weapon(this case Falchion) since when you merge and get those lil stat increase she'll learn that along with all the other skills you had on your already 5* Marth.
-This is a method I use on all GHB units and heroes I've had dupes of but a bad 5* better 4* hope this helps!!!