The one rule to rule them all
Patience, because you won’t be a native speaker in a few years, but you can reach a stage where you can converse with people and read some literature.
Ignore script early on if possible
Unlike other languages that use the Latin script (e.g. Spanish or French), we normally have to learn another script when we learn a 2nd or 3rd language.
In some languages, we have no choice but to learn the script to make out words and absorb the language. However, in other languages, usually the ones with more speakers, there’s some resources available that allow us to learn the language without reading script.
Granted, transliteration methods (i.e. writing the target language in another script, in this case the Latin script) may be standardised in some languages, like Mandarin, and not standardised in others, like Tamil. In this case, standardisation means that there’s an official way of representing the language in English. Mandarin has pinyin, but Tamil doesn’t have an official way of representing the language in English.
But in most cases, using the Latin script eases the transition and allows you to pick up essential grammar and vocabulary before learning the script.
Listening and speaking are precursors to reading and writing. Being able to form sentences through sound alone, written down in a script you understand, allows you to more easily transition to writing in the target language afterwards as you’ll already be familiar with vocabulary and grammar beforehand.
Treat difficult parts like getting to know a stranger
When you’re tackling a passage that’s moderately or quite difficult, just take a sentence and really understand it. Treat the sentence like you would a stranger. How does the sentence sound like? How do the characters look? Does the sentence remind you of other parts of the language?
Then get to know the sentence better. How does it work in relation to other sentences? Can you explain the sentence to someone else?
Then do this over and over for the different sentences and for different paragraphs.
If you want to sound native, pronunciation matters more than grammar
You can get away with grammar mistakes if you sound like you’ve spoken the language all your life. This also means that even if you can form perfect sentences, if you have a foreign accent, you won’t ‘feel’ like a native.
Having said that, don’t put pressure on yourself to get the perfect accent early on. For example, mandarin speakers like to emphasise that without tone, you’ll never be able to learn Chinese properly. If that were the case, it would be extremely demotivating to learn any Chinese as you wouldn’t even get near the fun parts. Even if your tone is imperfect, the context will allow your conversation partner to understand you.
With thanks
To my friend Tai and my other friends for discussion.