I'll just go out a pick a random comic and take a look at it. If the art and/or story grabs me, I'll binge read it. If I want more, I'll sub.
I've had a few other creators message me about their comics, and I'll always give them at least a quick look, and read more if it looks interesting (I started reading yours that way).
I do a regular "My favorite webcomics" on Twitter where I send out a tweet every time a comic I read puts out a new page. I'll occasionally be asked by a creator "How do I get on the list?" My answer is you have to be a comic I like and read.