Good question. There are many factors and sometimes it is just an impulse buy. Mainly I would say 3 things

1. Blends. I try to pay attention to what blends are used in wrapper, binder and filler. Lately if something has a Pennsylvania or Connecticut broadleaf in it I will pay attention, for example. So I try to remember what the blend is in a cigar that I liked and if I see another cigar that claims to have something similar I will likely give it a try.

2.Brand. Some brands just do not have anything I like so I dont buy and some brands are more to my liking and I will venture into something new from them. Alec Bradley has the Black Market which i like so when the Black Market Vandal came out, I tried it and now like it more than the regular Black market even though I am breaking rule 1 about blends cause I have no idea what the Vandal blend is. Other brands I have tried are just too strong for my taste so I avoid them.

3. Reviews. I listen to the comments and reviews here to see what people say about smokes. Lots of good info here and some people actually seem to like the same smokes I do and I check out some other cigar sites that have good lists of reviews. Dont pay too much attention to the reviews associated with the makers themselves but those of real people who smoke them.

There you are, a long winded answer to your question and sometimes I just buy 1 at the local B&M cause the guy there says its good. Lack of will power is also a good reason