I have found a couple of things really useful.
The first is to have a few really small tupperware pots - I have a couple that are about 1"x1"x2" and one about twice that size. I have another that's big enough for a small salad and another cylindrical one for soup. This are the good type with the clip on lids.
The second key thing is to have lots of different things in the fridge, so that you can vary what you put in the pots each day. A quick peak in the fridge would reveal (in addition to salad stuff), cooked beetroot, cooked meatballs, greek yoghurt, a bowl of red berries, silverskin onions, sun dried tomatoes.
I also have pilchards, peppered mackerel, peanuts and cherry tomatoes.
In the morning I always put peanuts and greek yog with fruit in the smaller pots and today I had onions, meatballs, beetroot and sun dried tomato in the 3rd. Then I took some soup (Waitrose essential is good and lowish carb).
That way I get to snack and can eat mostly anywhere. You can even have the soup cold and drink it straight from the pot.
It takes me about 10 mins in the morning, but I do it just before I go out and once I've had breakfast and a shower. It's quite fun really.