I care more about food than anything else on holiday, so it would be impossible for me not to do a little bit of planning and research. However, I don't do all of it. Sometimes, I just research an area of a city I'd like to visit and eat wherever takes my fancy. Other days, I might have a list of places I'd like to try, and if our exploring takes us in that direction, we're sorted for lunch. This keeps you in control without making your holiday feel a bit like you're just ticking things off a list.
Top tip: Have three must-visits. That way you ensure your top-tier choices are ticked off the list, and you won't be too sad about missing that amazing lunch spot if something else fun comes along.