1. How often do you print your images?
2. What size do you typically print?
3. Do you stick to the 300 DPI guide line or do you have a different approach?
4. If so, do you interpolate the resolution to get enough pixels?

My answers:
1. Not a lot, but I've definitely printed more the past few years. My home office has 7 of my images hanging. I have a storage box with another 25 or so images in it.
2. 11" x 14", I've never printed larger.
3. Yes, I typically try to keep at least 250-300 DPI.
4. No, most of my photo career has been with the original 6D. As long as I have not cropped significantly it is not a problem to create good 11x14s without needing to upres.