I think there are lots of good reasons to use a spread, from helping to focus your mind, to aiding memory with visual stimulation to imbuing extra meanings in patterns.
I like to choose a spread that appeals to me/querent/question and very often make up my own when I want specific details. I did a reading at weekend and created a "what do you want" spread for the querent, it ended with Qu Wands (don't want) wistfully gazing at the back of the 3 wands (want), the querent was struggling with whether or not to leave a relationship to go travelling overseas indefinitely/become nomadic.
At a querent's request I did a celtic cross (cc) though I rarely use it myself, here the middle card was surrounded by the most cheerful of the cups, without even interpreting the individual cards, the picture was striking.
My conclusion is I like some spreads, I don't care for others & when I don't find one I like, I make up my own, thats the beauty of tarot, do what feels right to you!
Sent from my Nexus 5 using Tapatalk