Fill level on screw caps?

[Maineiac]

How much head space should I leave on my 750 screw cap bottles.?
Also on new bottles. Do they need a soak in a cleaner or just a rinse and spray with star san?

 

[Yooper]

Fill the bottles to the narrowest part of the bottle, into the neck.
I wash mine to make sure they are clean, before sanitizing them.

 

[Bocochoco]

Yeah a real quick wash and sanitizing is all that's required for new glass. I dunk a few in StarSan in a bucket until I have everything ready then swap them out with new ones as I fill and cork.