Ok so i may be still a bit new to pmc but ive found these methods especially helpful to level up in pmc and become the next Disco_ :D

-Start a project and keep updating it. A adventure map for instance can gain many subscribers if its a fun and long map. But diamonds dont come in for free you have to talk with your followers ask what they would add in the map and they would probably diamond and sub to you which can gain u a quick 15 experience i believe. After that if you continue a adventure map you will slowly gain more views diamonds and subscribers.

-Start interesting blogs Everyone want to read a nice interesting blog about minecraft or else.

-Make a mod, A mod attracts especially cool ones go make a mod maybe adding candy as a food idk anything will get u alot of downloads that give u 2 exp each download and a subscriber and diamond every few players.

-upload a texture pack, make all the blocks look really cool or follow a cool theme like the avengers theme (that idea is probably taken already)

-All level one players!!!!! MAKE SKINS SKINS ARE THE EASIEST WAY TO LEVEL UP AT THE EARLY LEVELS ENTER CONTESTS TOO AND MAKE SKINS JUST DO IT, JUST DO IT hehe i said do it (my 6 yearold brother wrote that)

-Compete in each competition, Whether its a skin competition, tutorial competition or any competition, join em it s a way to get ppl who are looking at the contests to see your projects and possible earn a subscribe a a few diamonds. also i find it fun to join them so do it and the exp will be in your hands

comment back telling me what worked for you, diamond and sub for more cool blogs thanks!