Everything goes inside the panniers. I don't strap anything directly to the racks. It is simply too inconvenient. Depending on the tour I take either two or four panniers.

I also use an extra bag to supplement the panniers and hold small personal items. This is a handlebar bag, saddle bag, or half frame triangle bag; depending on my requirements for that tour. The last few years I started touring with aerobars again so the handlebar bag gets used less now.