Analyzing past diet attempts

I've been thinking back to previous diet attempts in order to puzzle out what did and didn't work.

In 2005-2006 I lost 75 pounds (from 273 to 198). The first half (2005) was "accidental" - a result of illness and crazy life stuffs. The second half (2006) was more intentional, though I wasn't tracking or counting anything. Based on memory, I think I was eating low carb and wheat free. And I exercised 5 or 6 days a week, mostly doing water aerobics but a few other things also. The weight came off pretty effortless until I hit the 190s and then I stalled. Why did it stop working? My guesses are that I needed to lower my caloric intake and switch up the exercise routine.

In 2010 I lost 32 pounds (from 240 to 208). I have pretty detailed records from this weight loss attempt. I lost the first 20 or so quite easily by going wheat free and monitoring my calories. Then I added wheat back to my diet. I started running, and I was subtracting exercise calories from my daily total. If I ate 1,900 calories and burned 500 calories I'd log it as 1,400 calories. I really struggled to lose ten more pounds over the next six months. I probably wasn't burning as much from exercise as I thought I was so I most likely was eating too many calories. And the only exercise I did was running, so there was no variation in my routine. My daily carbs were usually between 100-120, which is lower than most people consume but probably too high for me. Wheat is an obvious culprit as well.

So I'm thinking that to continue the weight loss that has been effortless thus far I need to:

• Continue to monitor calories. My only concern is that I'm currently eating about 1,300 calories so I don't really have much room to decrease calories if I need to. Maybe once I start running I'll be more hungry and want more which will give me more room to decrease if necessary. 
• Continue to keep carb intake below 70. Lower it to 50ish if needed. 
• Continue to avoid wheat. I may start adding some wheat free things if I can do so and stay under my carb allowance. 
• Add some exercise (I've really not been doing any exercise at all) and not get stuck in a workout routine.