False Friends of the Slavist
en.wikibooks.org
en.wikibooks.org
My point is that false friends are blurring the border between the two languages in your brain, they are confusing because they make you think of something in the wrong language. A solution to reinforce the separation of languages in your brain is to only think about them in the context of their own language, as soon as possible.
I'd listen to my Polish friend speaking and I'd think, I know what he is saying because I hear familiar words, but then I get confused as they mean different things.
One might think how through history one word got the opposite meaning.
I do speak Russian, and a little Czech and Spanish, but not Romanian. It's my vague understanding that Romanian is closer to Latin than other Romance languages. But the accent can sound Slavic, even though the words are almost Latin.
Also, Russian does have French and English loan words. And for ones that overlap with Romanian, they sound a lot alike.