Sometimes, when the mood is upon me, I write about my 'linguistic' experiences with the languages I am learning. What has worked for me, and what hasn't, and so on.
I speak Spanish. I'm not bothered about definitions of 'fluency' or 'conversational' ability and the like, but I when I started learning Spanish I wanted to be able to speak it to a level where I could chat about most things.
I got there in the end, and am still learning. I don't like using the word 'learnt' in this context as it has connotations of having 'finished' in some way, which I haven't. Learning a language is a journey without end or techo (unless of course you get fed up and stop). I'm still learning, still improving, and still making plenty of mistakes.
Everyone learns in a different way, which is why there is no one best method of learning a language, and also I believe explains why learning a second language is a different experience from learning a first. You have learnt how to learn this particular skill, and more or less an approach that will be successful for you.
I sometimes think that language teachers forget this. Once you have learnt how to approach a task, whether it is language learning or something else, it is easy to forget the route.
One thing that will remain constant for everyone is that its best to have no shame when you speak another language. No shame, no embarrassment and no worries about mistakes. The only way for me to speak perfectly, is in English. And my English accent is pretty good, although sometimes I say 'wanna' by mistake;)
I started learning Spanish in a formal sort of way through the Open University. There are pros and cons with this approach. The biggest negatives are cost, set syllabus and not enough emphasis on speaking. The biggest positive is that you are obliged to study.
But I really started to learn Spanish through chatting with native speakers week after week in various language exchanges, and reading. The most important thing (and this is very valuable), that I learnt through the Open University course, is how to learn a language.
In a nutshell, my approach is to gain a brief overview of the grammar using a Teach youself type book, and then read (listening to audio), and then at some point find a teacher for weekly conversations. Before this I'd learn sentences that were relevant to me from the sentences on Surface languages.
I'm experimenting with this to learn to read Afrikaans at the moment. And so if I was starting to learn Spanish again, I would not do a formal course, and I wouldn't spend money on anything other than a few books and regular lessons using a site like italki
I like books. I like reading. I also like talking, but you can't always talk, and you can always read, and when I can't talk I read.
I think a grammar book is essential, and here is the one that I use which is the Oxford minireference Spanish Grammar, priced at the pretty reasonable £0.01, or less in euros or dollars.
It is the only one I have ever used.
Grammar is distinctly frowned upon by the fast and furious crowd nowadays, but personally (as long as you don't go overboard), it is essential.
I'm not saying, ahem, that I would sit and read a Spanish grammar book. No. The book is for reference purposes. But well, para gustos hay colores 'one man's meat is another mans poision', 'horses for courses' and so on.
I also have a 'physical' 'dictionary, which is the Collins Spanish Dictionary and very good it is too, and the Oxford Spanish dictionary on my iPhone.
Word reference is probably the best on-line dictionary, and has the advantage that the attached forums give plenty of example sentences. These are necessary as many words (in Spanish) as in English have more than one meaning, and the sentences can clarify this.