Write long, publish short
One of the principles I follow is to write long and publish short.
There is a conventional wisdom in starting short - making a series of short drafts. And then expanding each into long form. Do that if writing long form is your goal.
If you want to condense your words, try the reverse. Write out everything you want to say. Make it as long as the words allow. Carve your message in prose. Don't hold back.
When you are done, start prunning. Remove words that won't be missed. Remove words that are not essential to the message. Remove preambles if the message can speak for itself. Remove anything that isn't clear. Remove anything that can be skipped. Remove anything that may prevent the reader from rising to the occasion.
Keep removing until what is left is beautiful, clear, and communicates what you want. You get a bonus if it's presented in ways that the reader can take action afterward.