Rachel’s got a great tip for babyproofing the stairs:
My husband and I have been wanting to install a baby gate at the bottom of our steps, but I didn’t want to drill into our banister. There are banister kits available, but they seemed pretty pricey for what they were. We went to our home improvement store and had them cut a 2×2 to the height of our banister. I stained it to match and then we attached it to the banister using zip-ties. Now we are able to contain our little climber with out having to damage our woodwork.
Related: Dog bed as staircase landing pad