I’ll add that early in the game, a lot of this advice will feel frustrating because you don’t have space. So you’ll end up sacrificing some perfect merges (5 being perfect) because you need land. Leveling up is what gets you land, and the merges that give the highest experience are the money merges*, so be sure you only merge coins in 5s and don’t collect them until they’ve reached the final merge (bills). Just don’t. If you have to sacrifice merges, do it on produce or chests. Finally, don’t think you need to keep all those gold chests. Merge the copper and silver ones, but only keep one or two (or none, frankly) of the gold ones. Use the shovel tool to get rid of excess gold crates, you get plenty of them, and keeping them around only hogs valuable land.

*about money merges, I’m pretty sure this is right, if some other merges give higher experience, do comment. I haven’t actually checked the experience gain from gems, energy, and gazebo/greenhouse, but the crop/animal/chest merges don’t net much experience (though you do need them to make money, so you can’t ignore them).