I aim for 30% of calories coming from fat....(40% from carbs, 30% from protein.) It's pretty easy to track if you are using FitDay. For me it seems like a healthy balance.
To figure out the number of fat grams to aim for, multiply your daily caloric goal by the percentage of fat you'd like to consume and then divide by 9 to get the grams.
For example, I aim for 30% of 1860 calories.
1860 daily calories x .30 = 558 fat calories / 9 = 62 grams of fat
Based on recommendations from the American Heart Association and other such institutes, I also aim to keep fat about 20-30% of my calories -- though I try to do that over time (say a week), rather than worrying about going over once in a while. I use nutridiary to track everything.
Also, some fats are better than others. I try to limit trans fats (though do eat some microwave popcorn with it), and increase the fats in olive oil and fish. This week I've eaten a lot of salmon (5 times I think!), so while my fat intake for the week sits at 31% I know that a lot of it is from the fish, and don't worry about it so much.
I've found that I've changed over time, as well. WHen I first started I just worried about portion control, then started counting calories, and then keeping track of other pieces of the puzzle so to speak.