I think this is a very important part of the creative process. It's like putting together a set list for a live gig. What songs flow well together? What will keep the audience's attention? What will hook them in at the beginning and give the listener a sense of completion at the end?
I personally try to avoid grouping too many songs of the same key and/or tempo together unless the songs work really well with each other or there is a theme in common. Currently I have a list of working titles ready for an album that is yet to be written and they all follow a theme. This is the first time I've had the luxury of doing this but like writing a novel where you map out the plot I'd like to apply that mentality to my composing. Nowadays people go for the one of tunes and the idea of listening to an album from start to finish is fading but personally I like listening to albums to completion. The added benefit is in todays music world if you follow this approach people may not just download one or two songs, they might purchase the whole series.
But as with everything artistic this is all very subjective. Try different arrangements and take a week or a month or a year mixing and matching to see what "feels right" to you or ask the opinions of your friends/fans.
I used to get into some pretty heated arguments with my bandmates about set lists back in the day and one band actually broke up due to one of those arguments. It's that important sometimes.