I need help writing a text message

There are a lot of people I used to work with that were somewhere between friend and acquaintance. I want to keep in touch via text once every few months. The first time I wrote

Just thinking of you so I figured I’d reach out to say hi. Hope all is well!

The second time I wrote

How’s everything going at [where they work/study now]?

What would be other messages I couldn’t send? I don’t want to keep using the same two.