Daily Calorie Goal

Since I've started really actually counting calories, I've run into a couple puzzling things. First, some articles I've read recommend to start eating the number of calories that actually sustain your goal weight to get used to eating that amount right off the bat instead of stepping down. This site and others have indicated that stepping down your caloric intake as you lose weight is a better idea. My problem is that honestly since I've started I'm having a problem getting all the calories I'm supposed to have. I know that you're not supposed to go below 1200 a day, generally, and the number of calories to maintain my goal weight without exercise would be 1870 (using the rule of pounds x 11), and the recommendation on this site for my calorie goal is 2040. I figure if I stay between 1870-2040 that should be fine, but my question is this: Does anyone know if I can decrease my daily calories below the goal on this site to increase weight loss rate but not put my body into a mode where my metabolism would slow down?