I read over the entire piece, to get a sense of content and flow.
I delete words that Mando’a generally drops (such as articles) and reword any flowery phrases.
I replace all the words that I can find in the Mando’a dictionary.
I look up each remaining word (translating it to English first, if necessary) in an English dictionary (to get the meaning in simple words that Mando’a might have) and in a thesaurus (to find possible alternates that might be in the Mando’a dictionary) and try out different phrases until I get something that seems least likely to be misread.
Mando'a dictionary that I use: https://mandocreator.com/tools/dictionary.html
English dictionary and thesaurus that I use: https://www.merriam-webster.com/
Another English dictionary and thesaurus that I like: https://www.collinsdictionary.com/us/
I put everything together and try to make sure it still makes sense when I translate it back.
Some additional tips for translating certain words and phrases from English to Mando'a: Gaa'tayl par johamur
Video walkthrough of a translation: https://www.youtube.com/watch?v=rnWyT1Y8Eto
Video from Mando'a Lessons about translating: https://www.youtube.com/watch?v=OZwZI7iTR7Q