Estimating is fine, if you're not a lard-barge that can only taste butter, velvetta cheese, and corn syrup. I've never counted calories, as in annotating the exact caloric content of everything, that sounds tedious and would make me sub-conscious about everything I eat. I just know what proper portion sizes look like, and know the general caloric content of said portions. Even if I don't know exactly, I can judge how many calories are likely in it based off of what it's made of or how it tastes. Also, I weigh (pun intended) on the side of caution and overestimate my calories when having a meal or snack. That way I never overeat, and if I under-eat, I'll just be hungry sooner than usual, and have small snack to quell it. You can always eat more food later if you don't have enough, but you can't take it away if you ate too much.