I used to have one slot alloted for a combination of two weapons used by my monk - but, alas... I don't recall how - any suggestions?

Just drag them both onto the slot with the primary weapon first. I would recommend you have them equipped when you do it. If it's just a bow or something, it doesn't matter; just do it from the inventory.

My Rogue always uses 2 weapons. I keep a few different combos in the slots to switch up fast.

Many thnx

Word ;)