Reddit reviews Planning in Plain English: Writing Tips for Urban and Environmental Planners

This. So much.

I also do a lot of work for DOTs and other agencies as part of the NEPA process. While the writing required is no doubt technical at times, it also must be tight and legally defensible, and there's a difference between that and useless jargon and plannerese.

In undergrad Planning in Plain English was required reading for our senior capstone class. It's definitely worth a look through if you want your writing to sound informed and thoughtful (to please your client) and at the same time accessible (to please your intended audience).