I use the grobag from bumpto3. Its brilliant.
whn I used blankets before, I had the shock of my life to see little baby Jacob pull the blanket (which i had tucked into the sides of his carrycot) over his head. As soon as i saw that, I went online and ordered a grobag.
2.5 tog with a sleepsuit when its a cool night
0.5 tog with a sleepsuit when its a summer night (but he has been in just a vest when its been absolutely baking hot a few nights this summer)
For winter, with your baby bing 6-9 mths, Grobag do the 6-18 mths I think. I need to get one of these actually. Jacob has been using the 0-6 mths ones. He is now approaching 7 months and is 73 m in height and his feet will be soon getting to the bottom of the grobag. The problem is I just don't know which colour/pattern one to go for!