What kind of alliance are you looking for?
I like to be in an alliance with high average score (=active members) and where they use the in-game forum for game related discussions. Maybe use discord just for off-topic chat and add a few rooms for game chat like ops/support.
Usually i join the alliance with the most members closest to my town (
http://grepointel.com/map.php) for easy support and help in city conquests and most important to join before your beginners protection runs out. It's always awkward to join an alliance with players you recently cleared.
Going to play active on 100 and use other morale servers to play turtle and earn some gold.