Hi, Michael. I do it all of them but I have difficullties in speaking and listening. But when native-speaker talk to me , it makes me remember sentences and know the meaning. Because they talk and do action. I am playing a film in my mind when someone talk. For example, pass me the tape please. The speaker poin to the object. Oh I know what should I do and grab it and give it. I think practice with textbook and speaking with a native-speaker face two face in real situation will work on me. 

I'm going to assume you mean "learn" in the Krashen sense. I use books while self studying. I think this is much more efficient than relying on a teacher.

Of course, actually acquiring it will take lots of input and usage. For this, practicing with a native speaker, teachers or language partners included, is a must. All other skills reinforce it too. Reading and listening show you how it's used. Writing is a good low-pressure way to practice what you already know.

Actually ....in my opinion ,the most difficult part for me is exactly spoken English. Sometimes you just can t open mouth or say sth, and lots words you know woule just slip your mind when practising with partners. Thus, I think I also need some help and methods of speaking as well as u.

 As for listening and reading , types are evrywhere. Buy some English magazines according to ur level (English Square recommended ). And visit some learning webs, such as BBC learning English......

Lastly, writing ,just text a short essay on ur phone or computer daily ,or make a diary as a routine. 

Ways of learning Eng are everywhere,it just depends whether u d go for.

When I see a sentence that baffles me, I check at first whether I really understand the sentence structure then if the grammar is contradictory to my knowledge, I will check the grammar reference to confirm the knowledge of grammar in my database and make sure I am really understanding the sentece in all apsects.