When I had been teaching about 3 or 4 years, I went to our annual state math conference and attended a session on problem solving in algebra I. One of the things the presenter taught us was the importance of what she called "turn-around words".
Turn around words are words that cause the number to be written after the variable. The turn around words are "than" and "from".
Anyone who teaches algebra I knows that students have trouble writing an algebraic expression for "4 less than 3 times a number" or "13 subtracted from a number is 20." They want to write 4 - 3n and
13 - x = 20. When I teach this, I have the students circle any turn around words and then draw arrows indicating that the 4 will be written after 3n and 13 will be written after the x.
I also have them stand up and I read out the problems and every time they hear me say "than" or "from" they have to turn around. This physical activity helps them remember the turn around words.