I am so so tired of broken sleep.
Have four children, 6,5,3,1.5. My youngest will not sleep through the night. Ever.
He was bf until 9 mo. Then he would feed anything from every 2-5 hours.
The switch to formula - once we got the right formula/ bottle combination - gave us about a week of good sleep.
That was Christmas time last year.
He goes to bed between 6&7 with a bottle, will usually stir around the 10/11 - I think he's a really light sleeper so it's us waking him when we go to bed - so he gets a small, maybe 3oz bottle then. Then he'll wake anywhere between 2&4 again the only way to settle him is either a bottle or sometimes bringing him to our bed.
Then, he will wake anywhere between 5:30 and 7 and be up for the day.
Of one of us is up for work early (5ish) often he will wake then. I do everything I can to not wake him - shut bathroom door before light on get dressed in there eat breakfast at work- but still as soon as the door is closed he wakes.
Leaving him to settle himself back isn't really an option as he's sharing a room with his 6 year old sister, and even if he wasn't he'd wake them.
I've tried giving him water, tried a dummy, and we have tried leaving him but that has just escalated and lasted hours of crying.
I am just so tired and can't see a way out 
Any magic tricks to try? My girls were and still are excellent sleepers