I know I’ve just started out here, but considering that my first ever project posted got me ten levels (I’m actually quite impressed by people liking it) in a matter of months, I think it’s fair to say it’s about the reception of your content within the community, and quality over quantity.

I guess just do your best and make enjoyable content!

Cheers and good luck!

Being active on the forums, uploading stuff for the contest's, and just generally uploading some cool stuff and talking to people.

Leaving comments on other peoples creations also give a small amount of exp :p

Be active :D

What Cib said.

Also participating in the community helps as well. :) Reply to some wall-posts and bring others some diamonds, people will notice you sooner if you do.

You can also participate on the forums, and enter in some community events.

But ultimately, just be yourself and have fun, post the things you created that you are proud of, and the levels will follow soon enough. :D

Leveling up at a consistent pace is a result of being an active member of the community and sharing quality or thoughtful content. When you receive a diamond, favorite, view, download or comment on a submission you earn xp.

If you are looking to level up, focus on sharing your interests and personality through the content you are passionate about creating.

Posting mods or datapacks will get you orders of magnitude more XP than skins (which are the only things you've posted).

Although skinners don't usually transition to modders overnight, a good mod can get you up many levels. This is my suggestion is you want to level up faster.

What do you need a high level for? You can't do anything with it, it only grants access to some more titles.

What I mean is that I am on a relatively high level and I don't actually need it for anything except for the fancy title.
But if you still would like to have a high level post something other people might be interested in.