Good rule of thumb when varying sentence lengths/structure [duplicate]

Question

My question is, are there any good rules on how to vary your sentence length/structure to keep your writing interesting?

Eg. start out with shorter sentences and then start to lengthen the sentences... something along those lines.

I should add that I am writing an academic paper.

Answer 1

1. Just write without worrying about your sentence length.
2. Read it aloud, paying attention to the rhythms. When do you feel yourself wanting to break? When do you feel like slowing down? speeding up?
3. Edit.
4. Read it aloud to someone. You'll get those feelings of wanting to break, slow down, and speed up even more strongly.
5. Edit again.
6. Lather, rinse, and repeat.

So... no hard rules, but self-impressions as you speak the words aloud and hear them. (You can hone your rhythm-sensing skills by listening to others read their work, too.)

Answer 2

My sentence length varies greatly depending on the circumstances. When my characters are doing something, particularly something that is either rapid or requires their full concentration, my sentences become short to reflect the pace of what is occurring - either in thought or deed.

There are times when my sentences become longer, in pace with the pace of the tale or as a reflection of the character thinking these thoughts. Some of my characters, having a military background, think in shorter sentences, while others tend to wax a bit more poetic in their rumination.

I go with whatever feels right to the character and situation. Sometimes a longer sentence will improve the flow of the narrative.