Wood tools are your friend. Don't destroy them. Don't lose them. Don't try to create anything else.
Wooden tools are a thing we often look over and we rush to stone tools because it can mine iron for a pickaxe so you can mine diamonds for a diamond pickaxe so you can enchant or go to the nether, but ive never seen much experience given for one tool in particular!. Sure your diamond pick can mine every ore and your sword has the highest damage but what if those diamonds couldnt simply be crafted with diamonds. The mod i propose is a skill system to minecraft mods that allows for all tools to start at +1 damage and the mining level of wood as well as speed of wood. The diamond sword you dreamed of would be weaker than your tradition wood sword. Swords and tools in order to begin upgrading must be made of wood (it doesnt matter either way because you cant afford to make a stone one).
It really functions simply i would hope, the more stone/coal you mine (stone should yield less than coal), more mobs you smack, more trees you chop, and more gravel you dig would slowly allow you to gain experience that would then upgrade your knowledge of the item you mined and your wooden pickaxe will be able to mine iron. The items required to level your stone experience would not be simply stone and instead iron which from there it would upgrade itself to gold, then redstone, then lapis, the the long awaited diamond level of your wood pickaxe. I would hope the pick would replenish itself of durability and gain some more ever upgrade because other wise your going to be making a lot of wood tools.
Something i always wanted in minecraft but always thought it would make a lot of rage is levels of an axe needed for wood, instead of just using a stone axe for every tree.
Oak- require a fist as to my knowledge it is the softest.
Spruce- One level up, those spruce trees you spawned in and you ran miles from, you can break with a wood axe.
Birch- Nearly the hardest in my interweb research, would take a stone axe.
Jungle- Oh dont complain that you cant break those huge trees you spawned in, look down and you can see your standing on oak, happy mining because you need iron.