One of the tricks to consider - it's easier to raise your BG than to lower it. So if you are having a hard time with the carb counts, take a bit more insulin for your meal and then if you start to drop, take a little bit of food to correct it. It might be an hour after a meal, or maybe two.
IC ratios change. Different times of day it might be different, and different types of carbs come in at different speeds, so you might need to take insulin earlier or later. And depending on where your BG is when you figure out the dose, you might need more or less. Higher BG's might need a different correction factor, not just more insulin.
Since all the carb counts can be somewhat guessed, your IC ratio might not always be the same, and your correction factors might be different, it might help you to guess on the high side, and correct with food.
To me it's a no-brainer. I can either guess on the less-insulin side, and need more insulin an hour later and fight a high BG, or I can guess on the more-insulin side, and I get to eat a little snack an hour later.
Toughest thing to learn is not over-correcting. Be patient with everything.
Also, if you are frequently going above a certain BG, make sure you have enough basal going, and also consider earlier dosing for meals. If you eat when your BG is on its way down, you can avoid the high alarms easier.