I also started to notice the waste in food production, not just what I was throwing out myself.
I decided to stay away from farmed animal products, because the extra land required to produce the food was indirectly taking away from the space available for natural habitats. I could hypothetically still eat hunted food (especially evasive species) and road kill...but access to these things has so far eluded me.
Fish is another thing that I have changed my consumption of, because wild sea fish are unsustainably caught and farmed fish usually comes with the same problems as pastoral farming (the exception I have found sop far is mussels). So mainly I am only eating fish caught with a rod from the wild (usually by my brother in law).
Eggs have snuck their way in, but only if the hens were fed exclusively on kitchen left overs, as I think the return there is better than composting. So far I have only got one source, but that will keep me going!
The only commercially produced animal products that I am not avoiding are gelatin and buttermilk, because the way I see it is these are byproducts of other produce and more is probably wasted than consumed.
There are of course many exceptions:
Food that is going to be thrown out-leftovers, surplus food, when a restaurant puts meat in your vegan dish or products that will be going out of date soon (lots of supermarkets have a special section) are fair game!
The starvation clause-This happened more when I was travelling in Colombia, where after a few days breakfast with no eggs was unavoidable, but usually it is easy enough to find a varied diet without animal products.
The invisibility clause-This one is pushing it a bit, and I have got better (having googled the ingredients of all of lidl's breads) but I was allowing myself to eat things that had no ingredients list but did not obviously contain animal stuff.
Having been following these general rules for 5 months now I find it is actually not difficult at all!