Personally, I think keto is a terrible idea. It's not sustainable long term and it hasn't really been around long enough to know if consuming the insane amounts of fat is going to have detrimental effects or not. It can't be good for the organs.
It's really quite simple: Cut refined carbs, not whole grains and beans.
As for snack ideas, you're going to get the same answer regardless of your diet, IMO. Except fruit, you're not going to be told to eat fruit as a snack in keto, but in reality it's just fine. Snack on some veggies or fruit. My personal favorite is homemade granola. If you don't want to go to the trouble (beware store bought granola due to the sugars), just a handful of almonds or other nuts. A can of tuna. Add a little peanut butter or cottage cheese to the fruit. Jerky is always good.