How can i get my son to asleep and sleep alone

My son is also 1 and a half. He has sleeping problems too as do many many other mums!! My baby boy has learn to get his blanket for a snuggle when he his sleepy and if he has had a very busy day then he crashes right out. I've started phasing out daytime naps so that he is more tired when it comes to 7.30 and actually wants to go to bed. He sometimes has a little cry when I put him down in his cot. Which he did quite a lot a few months back. What I did was put him to bed and tuck him in, pop the night light on, and leave the room, he would then stand up and cry and I would let him for only a minute or two and then I would go back in and lay him down in bed again. Then its a case of repeating that process until he understands what his cot is for and that your not far anyway because he see you every 2 minutes until he settles and falls asleep. After about 4/5 attempts of this my boy has always settled and thought what the point, she's only the other side of the door!! Hopefully I have been some help. You really don't want you baby boy growing up to clingy as he won't settle with nursery or school when he has to part with you when the time comes. Check the temprature of his room and also give him a blanket or cuddly toy that he recognises and you will soon get him into a better routine hopefully!!