Is it possible for me to create individual invoice reminders for each of my clients? Some prefer 3, some prefer none, but I don't see any way to do this.

Hey there, @kossa-bocagrande. 

Congrats on making your first post here in the Community! 

When sending an invoice reminder automatically, it will only occur once and to everyone. However, you can manually send reminders one by one to specific customers. Here's how: 

1. Go to the Sales tab on the left-hand menu bar. 
2. Choose Invoices. 
3. Locate the invoice you'd like to send a reminder for. 
4. Pick Send Reminder from the Receive payment drop-down.
5. Customize your message and tap Send. 

For future reference, check out this guide: Send invoice reminders automatically or manually in QuickBooks Online. 

I hope this helps answer your question. Reach back out if you have any other questions. Bye for now!