Am I unwittingly damaging my knives with amateur sharpening? I had a bread knife that took a trip through the dishwasher and was frustratingly dull.  I bought a cheap sharpening rod to attempt to salvage it (this one specifically:  https://www.amazon.com/gp/product/B001910FOA).   It was a bit tedious to get into all the serrations but it was like having a new knife.  I was so pleased with the results I took to using it on my chef's knives whenever they were dull and the honing rod didn't help, finding the results better and faster than the electric sharpener I have.  It seemed pretty straightforward and I didn't put a lot of thought into the technique, but the knives were definitely getting sharper.  I'd guess I did this every few months (frankly I tend to get lazy about honing which probably makes the edge dull faster).

I decided I wanted to get something nice to get them even sharper so I invested in a whetstone, but as I have read about using it I've become alarmed by the number of people talking about how you need to use a beater knife on your first pass because you're liable to do some serious damage to your knife.  Others even say you shouldn't even try to sharpen a serrated knife yourself!  Frankly I find it hard to understand how it's even possible, since it's a piece of metal and you should (I would think) be able to remove more to fix it no matter how bad your sharpening job is.  But I don't even own any knives I'd want to use for practice and not care if I rendered them unusable.  All this talk has made me paranoid:  could I be destroying my knives somehow?  How, exactly?
Destroy is too strong a word. For most knives the worst you can do by honing wrong is to take the edge off the knife. This isn't destroying it, it just means you need to get it sharpened again. Angle is the important thing with honing, you need to match the sharpened angle and be consistent. 

If you have a knife with a design or a pattern on the blade, like Damascus steel, some Japanese knives, etc. honing badly could damage that design or pattern and ruin the look of the knife. That doesn't destroy it, just makes it less attractive.