Listen! Listen! Listen!
Listening is the hardest and most important skill. Even if 100% of learning time was spent listening, I don't think this would be that detrimental. I think writing is highly overrated in many schools, it's only useful because it aids reading. At beginner level, writing is maybe useful to see the components/structure of characters.
Level for fluency
The number of words people claim to need fluency is sometimes drastically underrated. Can hear claims of say, 3000 words is enough for normal fluency. But as a quick example, you maybe know 200 country names, 200 city names, 100 animals, and almost none of these will be in those 3000 words that people claim. If fluency means every time someone says "obscure" words like octopus, karate, Peru or obscure (all of which aren't covered by the 5000 words of HSK6), that you have to ask what they're saying, then sure... you're "fluent". But really, words like these you'd expect every English native speaker to know.
My progress
My progress, I self-studied while working to HSK3 level over 9 months, then went to a full-time, slow-paced course in Taipei for 3 months, then a well-paced course in Shanghai for 5 months, reaching HSK5 level after the end of this.
I can confirm that a score of 60/100 at HSK5 listening is still below the level required to watch general television and understand it (in terms of everything: vocabulary, accents and speed).
Tools/software
Anki
I'd highly recommend the Spoon-fed Chinese Anki deck (but for the Chinese side, only recommend as a listening and not reading deck). I use as a speaking (translation) and listening deck, though I suspect the speaking side probably slows down the progress and is less useful. Downside of this resource is that it still uses English heavily since it's translation, rather than pure immersion.
I heavily used Anki, but it does have a mental downside of always feeling the need to have done more (see https://www.dannycrichton.com/2016/05/15/the-near-impossibility-of-learning-languages/). E.g. if I had a 2 week break and at this moment, ~2000 cards are due for review, which is at least a full day...
Pleco (dictionary mobile app) is fantastic, and has great integration with Anki. Much faster to make Anki flashcards through Pleco. So for efficiency, do not make paper flashcards and do not make Anki flashcards outside of Pleco.
Duolingo is a terribly inefficient use of time for Mandarin, AVOID. I found ChinesePod, at least at the beginner level when they still speak in English, also too slow-paced/inefficient.
For pronunciation, the very-dated but supposedly out-of-copyright-so-free US Foreign Service Institute resources are a great resource, particularly for beginnner's Pinyin pronounciation. I found it very useful until it became too difficult as a standalone resource. Note it is an incredibly dry resource, and audio quality is not ideal as it was probably recorded from a secondary source.
Italki is good, tutors vary in quality/style, I only ever tried informal/low-preparation lessons. Generally cheaper to have a one-to-one online lesson than an in-person group class at a reputable school.
Learning is mostly an exercise in memorising words/phrases. Grammar is useful but most of the time is not the "blocking" factor to communication.
Study in China (and get paid!)
The Chinese government is very generous with scholarships to study there, and the competition to obtain them doesn't seem very intense yet. I obtained a Confucius Scholarship for one term at Fudan University in Shanghai, but if you want to learn I would recommend, if possible, going somewhere 1) without international community, 2) with smaller class sizes, 3) with increase class hours. Most schools seem to only have ~3 hours/day (probably legal minimum for visa requirements), which was not intense enough for me as full-time language learning.