How do I switch between current scenes and flashbacks?

I feel like this is such a dumb question but I want to write chapters that have current things going on, but sprinkling in flashbacks throughout the chapter. I’m new to writing, so idk how to do it without it being confusing to the reader. Do you just start the next paragraph with a flashback and hope the reader figures it out, or do you put some sort of distinction in between current events and flashbacks. Any ideas are welcome.