Here's what I do.... (The only things "packaged" that I eat are condiments, yogurt, bread, and dry goods like pasta/rice, etc).
Before you cook, measure/count/weigh what you'll use for ingredients (including veggies)... Then just do general google searches and compare the different website's calorie counts for each food, choosing numbers right in the middle that match the amount you're eating.
Then, add up the total calories for all of the ingredients, and divide by the number of servings it makes... and then poof! You've got your calorie count for your portion
For example, if I make 2 servings of a pasta primavera, I'll add up the 2 plum tomatoes (about 13 each, so I round up to 30), 400 calories for 2 servings of pasta, 90 calories for 2 cups of broccoli. 30+400+90=520/ 2 = 260 calories per serving.
This gets quite a bit easier when you a.) stick to natural foods that do not require label interpretation and b.) you are diligent in writing things down. Eventually, you'll remember what each portion of each food is roughly worth in calories, and you can add it up in your head as you go! When I need to write down a calorie count for something that was at a restaurant, someone else's house, or that has a lot of different counts listed on different sites, I choose the higher number and make an effort to exercise a bit more to balance it out.
It's ok if one item isn't precisely counted... going with the higher calorie count will just set you up for success, if you've over-estimated the calories.
Hope that was helpful and not too basic?