That's a great question...a little dirty if you're a person always with their mind in the gutter like some of these folks.
I'd have to go with a lot of the people on here with Thumb or Index finger. My index finger does stick more than my thumb but i think it's because there's more force behind my index finger and less balance. If you know what I mean. The thumb just moves easier across the glass. If I'm using two hands then I'll usually use my index finger. If I'm using one hand then I'll just use my thumb. Wow, that does sound dirty.
I'd have to go with a lot of the people on here with Thumb or Index finger. My index finger does stick more than my thumb but i think it's because there's more force behind my index finger and less balance. If you know what I mean. The thumb just moves easier across the glass. If I'm using two hands then I'll usually use my index finger. If I'm using one hand then I'll just use my thumb. Wow, that does sound dirty.