ask about the different colors and types of thread. they will usually use cotton which is preferred by many. also, to add interest ask to see variegated thread, this comes in may colors and shades. next, if the quilter uses computerized machines, ask to see the different patterns, there are literally 1000's of different patterns to choose from. once i made a nautical quilt and he suggested using ships wheels, sailboats, and anchors and waves, this was really interesting and made the quilt pop. check my blog for details and pics. richbrot.blogspot.com.
they will stretch your top very tight, so make sure your piecing and joining have small stitches, i use a 1.8 on my machine. also i use warm and natural batting which is very durable and holds up to many washings.