If I'm not enjoying one, I'll toss it and start again. If it's a small cigar, I'll usually give it until the half way point or so to see if it changes, if it's a large cigar, I'll just get rid of it after a little bit if it hasn't improved. An exception to this would be cigars that are rolled a bit tight or are slightly plugged but that I think could be good. Those, I will keep smoking and working on because I've found that, with a little patience, I can usually open them up and enjoy them. However, if they're not smokeable, then they're not smokeable and out they go.