I always think of a sampler quilt as a great learning tool. Later you can use it as a technique reference. When I started quilting I picked patterns that would challenge my skill levels. I kept it uniform by using an anchor fabric in the sashings and a limited color palette. that way if I was having trouble I could tell my self..it is only one block. Having said that...remember the quilt is your creation, do what you want and quilt police be banished.