I’ve recently completed BenWhately’s HSK 1 and HSK 2 courses, along with Memrise’s Mandarin Chinese 1 course. I’m wondering what would be best to work on next?
I’ve been working on those courses for about 2 years and I’ve also recently started taking 1:1 courses with teachers in China.
I’m thinking about:
Taking HSK 3 seems like the logical next step to me, but if you want to try to branch out and try some other courses, I don’t think there’s anything wrong with that.
Since you’ve finished at least HSK 1, might I suggest this course of mine?
You could also check out this previous thread of mine for some courses that might be a fun break from studying more normal vocabulary:
I also have a couple of courses about the provinces of China here and here, although you might want to wait until later to learn those. Or not – up to you 
Okay, I think I’ll move forward with HSK 3 then. The measure words course looks interesting, I’ll give that a shot as well. Thanks!
Just wanted to echo neoncube and also add that Chinese Grammar Wiki is an awesome resource to get your grammar down. On top of this, there are user-made courses that test on each of these grammar levels.
On top of this, just keep in the back of your head that Chinese has a large investment needed in terms of vocabulary. You’re making awesome progress and the HSK levels seem random with all the root words learned but somewhere down the line, all the words will reinforce multi-character words.
Another resource is Clozemaster which you can use the important functions of for free. This basically drowns you in a barrage of hsk-level-specific sentences that you fill in the missing word for which gets your brain used to sentence patterns. If you have a desk job, just leaving this open on your desk and tapping the correct answer all day really helps.
Last, keep in mind that reading, writing, listening and speaking all reinforce each other. If you’re struggling to find the right word in speech or any situation, the amount and variety of connections you’ve made in your brain helps you recover. I started off only wanting to speak and didn’t learn characters. A year or two later I realized reading is very valuable and started with memrise. Now, 5 or 6 years in, i’m realizing that writing really cements things into your head. Right now I feel like I’d like to be able to write all the HSK 1, because I can use those roots to write more advanced levels from the memes I have of them in my head. For writing, try out TofuLearn which lets you practice writing hsk level words on your mobile and prompts you for reviewing just like memrise does. I found this one when looking for a free writing tool since the most mentioned, Skritter, is pretty expensive.
Again, just get yourself into the habit of learning 2 or 5 or 10 words a day, and sooner or later the main Chinese vocabulary grind will be done and you’ll be at that level where you can explode in practical usage fluency.