The best tip on the planet for punctuating properly…
I didn’t learn grammar at school. We were part of an experiment, taught to spell phonetically with traditional grammar mostly left on the shelf. In retrospect it was a brilliant way to learn to work – and play – with language intuitively. But to this day I wouldn’t know an adverb or past participle if it bit me.
Thankfully they drilled punctuation into us.
If you’re baffled by it, teach yourself the meaning of punctuation marks. There’s plenty of advice online. Then use your speech patterns to guide when and where you use them.
Read your copy out loud. If it feels or sounds stilted, tinker with your punctuation ’til the words roll off your tongue smoothly, as if you’re casually chatting with a friend.
Funnily enough a visit to Friends Reunited proved that everyone in my year, of every ability, can spell and punctuate perfectly. They write like demons, with personality and verve, and their intuitive fluency shines through.