I have two tips that might be helpful to some.

I often look out for a grocery store. It is easy to find things for breakfast and lunch - cerial, bread, fruit, nuts, drinks, salad etc. Dinner would be a bit more of a challenge, I've not done that yet. But, if I can organise breakfast and lunch, which I eat in the evening, then I only have to eat out once per day. I usually chose lunchtime as it is often cheaper.
Phone boxes. Here in the UK you can call from a BT phone box to any UK line, and it is only 60 p for up to 20 mins! I often use it during the day rather than my home phone just for the cost saving. It also probably works out cheaper than sim 'deals' if you are taking a phone from overseas, and you can always see how much the call is costing.