I test a lot of RPG from the workshop and here are a few tips for any beginner:
-Difficulty:
The player shouldn't have to grind to progress in the story unless he wants to.
Trust me your RPG won't be enjoyed if you need to spend 10 minutes farming basic monsters.Bosses should have higher ATK/HP but not be able to OS a full health member.Also you shouldn't put random encounters or at the least give items that activates/desactivates random encounters.If you give less than 4 party members remember that it means the player will have less people able to use items in battle which can be a problem in many scenarios for instance:"I need to cure the poison and heal the party member at the same time but I can't because I don't have enough party members able to use items".

-Gimmicks:
You may add many gimmicks to your game but if these are too specific, they may feel like restrictions for instance, limiting saving to save crystals. While the concept isn't new, it becomes crippling for exploration if you don't put enough of them, as it forces the player to always go back to the save crystal every time he faces new enemies especially if your game isn't well balanced in terms of difficulty.

Items:
Don't rely on random drops for the basic items like potions etc
these should be buyable in a shop or found in chests you should always test your RPGs without random drops to see if the player can survive while dropping nothing.Also ALWAYS sell items that cure any ailments in your game. Revival items should restore AT LEAST 50% health or the player will be trapped in the unending "resurection->gets killed by weak attack" cycle.

Money:
If you don't make your enemies drop money at least have them drop skin/tail/scales or any sellable item to get money because the player will need them to resupply his healing stach.

Map Design:
You can be inspired by the sample but please don't use them, everyone on the workshop does and it is annoying as hell.

Content and Scripts:
Always mention the author in the credits or the description or you may find yourself in trouble.

This should be it for the basics feel free to ask any questions I'll try my best to answer them.

Also <= Best Danganronpa waifu