Last night during the New Author Celebration Call with Donna Kozik, I was asked what I would recommend to an aspiring author whose native language is not English. In hindsight, here are my thoughts:
1) Write, no matter what. When you get stalled for an english word, even phrase, use the one that comes to mind from whatever language it is.
2) Are you writing something that can use both languages simultaneously? For example, in some of my song lyrics, I use both english and greek words and I know they will be used in this way. In my current book this will not work.
3) Are you using terminology in a specific language? Words of a specific origin/language carry a different vibration than if you were to just translate them. In this case, you may have to use your specific term and explain it in the language your readers share.
4) Lastly, remember that not being a native english speaker has its advantage in that you tend to use simple words to describe what you want to say. Thus, making it simpler and easier for readers to follow!
If you have additional tips please provide them below.