With a BMR of 1080 and a TDEE of 1350, I set my net goal at 900 calories a day (but I always eat more than that because I eat back my exercise calories)... here's my thinking...

1350 (which is my TDEE) X 7 days = 9450 (TDEE for the week) minus 3500 (to lose a pound a week) = 6090 divided by 7 days = 850 calories.

So each morning my net is set at 900 and I usually consume 1300 to 1500 calories a day.

Keeping net at 900 to me seems easier. Make sense or no?

Yes.

With at TDEE of 1350 and a goal of 900, you have a 450 cal defecit which is a little less than 1 lb a week (500 defecit).
3500/450= 7.8 days to lose one lb.

However, I am assuming your TDEE includes your exercise because your 1080 BMR x 1.2 (sedentary multiplier) = 1,296 TDEE, which is 54 cals difference a day from the one you posted (however, if you have a higher TDEE because you are a nurse or something and not your exercise routine, disregard this paragraph since you are correct). If your TDEE includes your normal exercise routine you SHOULDN'T log back/eat your cals because technically it is supposed to include it. I personally prefer to choose the lowest multipler and then manually add your burns so you might want to consider this. So with this assumption your cut is really only a bit over 400 (and you are manually and accurately logging your burns with a HRM and eating back), you will lose at a rate of 1 lb every 9 days (3500/400). But this rate is fine. When you don't have that much to lose, you have to go slow; anything over 1 lb every 14 days is totally acceptable.

You don't technically need to eat back your burns (otherwise it would just add to your cut), but since your goal is so low you should (which I think you are the way your post is) because it is REALLY hard to get all your vitamins, minerals, etc on just 900 cals. Just log your exercise in and eat them back and your net will adjust itself and your cut will stay the same.

I hope you have a HRM that tracks your burn because at your weight and height 500 cals a day sounds really high (not undoable though, just unlikely)

However, remember all of these are assumptions, we are ASSUMING your BMR is EXACLTY average for your age/weight/height, which is really rather unlikely. BUT we should be close. And you can tinker with it after you have a few weeks under your belt according to how quickly or slowly you are losing compared to your goal (if you are losing quicker, up your goal, if you are slower, you COULD drop your goal but I wouldn't suggest it because it would be even harder to get all the nutirition you need). Either way, you will start to see a trend and can adjust from there.