Servings are quite a bit easier than tracking every meal. Instead of plugging in weights and numbers, you can estimate "Have I already had X servings of Y today? No? Let's add one in." From the past few days of tracking, I've devised my perfect system.
For a total of 1100 calories (someone with higher caloric need would want to increase it proportionately), it came to:
8 servings of 6-8 gram portions of protein
3 servings (~80g/serving) of colorful veggies, with the focus, as usual, on dark, leafy greens
2 servings of fruit, with at least one being berries
1 serving grains or starches
~2 servings added fat
This is just a basic list; a skeleton diet, if you forgive the irony. If I feel like having more spinach, that's probably a good thing. And it's hard to eat too many berries. (Larger fruit, on the other hand...) I almost always find myself low on fat, so there's another lenient point. The biggest restriction is the carbs, of course. With the above plan, 1/2 cup of brown rice in addition to everything else brings me to 85g carbs total (ftr, it's around 70g protein and 60g lipids when I add up this example; a little more fat and cals in that would be perfect) which is under my limit of 100g. So, while it's not particularly something I want to increase, a carb here and there won't hurt. Someone with no meat and/or animal products would probably want to make this a high-protein carb like quinoa, for a little extra oomph. Also, for a very low carb diet, this could be omitted and more veggies, fruit, and protein added.
In the protein category, one 3oz portion of fish would count as 2 servings because it tends to pack 15+ grams of protein. Same goes for a half scoop of protein powder. Other options would be a serving of nuts or seeds, an egg, a serving of dairy, or a serving of soy/seitan based product. 8 servings is a lot, but there are many sources to get it from. Variety is an important part of this system - it's fine to have half the servings in one day be from eggs, as long as you vary it and be sure to have more than just protein powder, or else you'll be low on lipids.
As has been happening, the above leaves me (slightly) deficient in folate, B5, E, calcium, iron, phosphorous, potassium, magnesium, and zinc; though very high in other categories. 600mg of calcium in a mineral supplement, plus some occasional iron/folate/E supplements would round it off nicely. I have a hard time finding phosphorous, potassium, and B5 in anything other than small amounts or in complexes with urine expensifiers, but deficiencies aren't a usual problem, so I should be fine.