So recently I have been writing entries over at Lang8. I have noticed that one of my major problems is thinking in English or Spanish, and trying to say it in Japanese. Turns out sounding strange or just flatout wrong any idea's on how to avoid this? I understand sentence structure very easy (read) but when it's my time to write I sometimes mix up things. So any words,thoughts,idea's please share them.
How much native Japanese input are you getting? It seems to me like your brain doesn't have a whole lot of natural set Japanese phrases to fall back on, and so your brain is trying to construct them from scratch.
Naturally you fall back on English. However, I will say that this kind of thing just gets better with practice. As you get faster making sentences in Japanese this kind of thing will fall away, and your brain will stop using English for scaffolding.
I think that for beginners it's inevitable that they translate their thoughts from their first language to Japanese. But I agree that with exposure, experience, practice, time, vocabulary, eventually one learns to convey thoughts in the Japanese language.
So keep writing entries on Lang-8 and get feedback and study the good corrections well. Make friends there. The trick is to find the Japanese people who make good corrections. Converse with them in Japanese in the comments. And don't forget to help them with their English (or other language) too by making good corrections.