Hi Furball,
It was so easy i cannot believe it. I reckon the flask approach is easy, unless you have a range (which i do) Definitely don't need fancy maker.
I brought half a pint of semi-skimmed milk to almost boiling (kills of any unwanted bacteria).
Left it to cool to 50degrees . When it has formed a skin it's normally at 50 degrees. If you have a kitchen thermometer all the better. It needs to be 50 degrees for the good bacteria to work.
Then a spoonful of live yogurt mixed with a little more milk just so i could pour it down the side of the jug so i didn't disrupt the skin on top. I covered it wrapped it in a teatowel and left it on the range overnight. Took me all of about 10 mins.
Without a range, i would put the boiled milk to cool in the open flask, then add the yogurt and close up till morning.
Next morning half a pint of live yogurt!!
Then, i poured it into a muslin over a bowl and let the 'whey' run into the boil. An hour later i have a pot of greek yogurt.
I'm hooked now.