For me there are two main types of exercise:
where the exercise acts as a prompt to write e.g. provides a theme which is more important than any constraint in terms of format (e.g. useful in a perceived case of 'writer’s block');
where the writer is challenged to do something outside their comfort zone or where the constraint is significant enough to force them to try something new / look at language in a different way (e.g. writing poetry to strict formal rules).
Here are some examples of type-2 prose exercises you might want to try.
Write a short first-person story (200+ words) without using the pronoun “I” and/or “me” - or both! - anywhere in the story. When I did this many years ago I attempted to write the piece from the perspective of a schizophrenic, so there were two of me! The story must come across as first-person, otherwise it isn’t a challenge at all..!
Write a short story (200+ words) without using the word “the” anywhere in the story. This can be a useful exercise in terms of discipline and finding alternative ways of saying the same thing - as are all four of these exercises. [If you want to you can substitute other common words for ‘the’ e.g. ‘a’, ‘that’ etc.]
Write a decent length short story (500+ words) without using your ‘go to’/‘lazy’ words. Writers have words they fall back on all the time; words like “it”, “that”, “like” etc. If you want to surface what yours are, find a ‘word cloud’ tool on the internet (there are free ones) then have it analyse a fair chunk of your prose (maybe 1,000-2,000 words). You might be surprised at the words which pop out as being used most frequently. In this exercise you consciously write a piece without using those ‘go to’ words.
‘100-word challenge’. It’s harder than it sounds. Write a piece of flash fiction with a maximum word count of 100 words. And don’t be tempted to cheat! I’ve known people get their story down to 120 words and then give up as it becomes ‘too difficult’ and they don’t want to compromise what they’ve written. But it is difficult; it’s meant to be. This is an exercise which forces you to consider every word, find where three can do the job of four or five, or where you just have to remove a phrase you really like. Great for enhancing skills like editing, getting distance from your work, being objective and inventive etc.
More exercises soon. Have fun!