Sending emails and texts to clients who have already ordered isn't just wasteful in terms of S+ services you're paying for, it also makes you more likely to get hit with a SPAM flag or unsubscribe by a client.

Here are a couple of ways to do it:

-Triggers can exclude people who have ordered in emails
-Triggers can be set to update to a ~Session Order Placed Status by invoice creation yet triggers that send emails can target the existing ~Session Done But No Order Placed Status so that unless an order gets placed, a trigger won't just move a no-order-placed email to the next (i.e. order placed) status

These aren't the easiest ways to get it done, but reputation scores are serious and limiting customer pings is just good housekeeping.