When it's below 50ish I always use a primer disk. My disk is like super heavy weight aluminum foil. When I'm ready to boil, I will put as much fuel in the stove as I think all need to get a boil.Temp and how much water I'm using dictate the amount. Usually .75oz to 1 oz.. then I put around half a teaspoon fuel (maybe less) in the disk. One match lights them both. I then slowly (10-15 sec)lower the Kettle down to the stove. If it is cold like 30 down to around 20, I may have to hold the pot just over the stove for 30 - 40 seconds. I put the wind screen so it hugs the Kettle(1/4 inch all around). Some time I'll put a small twig or two under the screen, to add air flow upwards.
I had to figure how to make this stove work in the cold, because I had no plan "B" and really did not want a cold supper. I know there are faster, more efficient methods out there. This stove is one of my favorite pieces of gear. Weight of 1qt Kettle, under disk, stove, wind screen, matches (in an old school steel holder) Mini-bic, 12"x12" MSR towel and stuff sack = 10.8oz