For example, since a week, I try to read an English article all the days, write a post on italki and talk with an English friend every day between Monday and Thursday because I don't have more free time. I also write down each word that I don't know and listen BBC radio. In my opinion, talk by skype is helping me a lot.
Hey Carlos, keep up the good work. Here are some suggestions on how you could improve your writing.
since a week ago
I try to I've been trying to
all the days every day between from Monday to Thursday
listen to BBC radio
talk talking by Skype
"because I don't have more free time" - consider saying something like "because that's when I am free" instead, since it sounds more natural.
Anyway, since I'm studying Japanese, beside the grammar drills I do online, lately I've been trying to memorize technical words related to my professional field using flash cards, as well as trying to translate and interpret the lyrics of my favorite songs. It is both exciting and challenging at the same time, so I think it's a good way to boost your skills in a foreign language.